diagnosis and testingww2.justanswer.com/uploads/sdcrowder/2010-09-10_040249_abs_diag.pdfsep 10, 2010...

206-09-1 206-09-1Vehicle Dynamic Systems

DIAGNOSIS AND TESTINGABS OperationAnti-Lock Control — Traction ControlWhen the ignition switch is in the RUN position,and Stability Assistthe ABS module does a preliminary electrical checkand, at approximately 20 km/h (12 mph), theSpecial Tool(s)hydraulic pump motor is turned on for

73III Automotive Meter approximately 1/2 second. During this time a105-R0057 or equivalentbuzzing or humming noise may be heard and avibration maybe felt in the brake pedal. This is anormal condition. Any malfunction of the ABSdisables the stability assist and the ABS warningindicator illuminates. However, the power-assistbraking system functions normally.

Flex Probe KitThe ABS module monitors and compares the105-R025B or equivalentrotational speed of each wheel. Wheel speeds aremeasured by the wheel speed sensor, whichelectrically senses each tooth of the sensor ring as itpasses through the magnetic field of the sensor.When the ABS module detects an impending wheellock, the ABS module commands the hydraulicRotunda Active Wheel Speedpump motor on and commands the hydraulic controlSensor Testerunit (HCU) to open and close the appropriate105-R0110solenoid valves to modulate the brake pressure tothe individual brake caliper(s). Once the affectedwheel(s) return to the desired speed, the ABSmodule commands the HCU to return the solenoidvalves to their normal position and normal base

Vehicle Communication Modulebrake operation is restored.(VCM) and Integrated

Diagnostic System (IDS) The ABS module must be configured when a newsoftware with appropriate ABS module is installed.hardware, or equivalent scantool Traction Control

When the drive wheels lose traction and begin tospin, with vehicle speed under 100 km/h (62 mph),the ABS module commands the hydraulic pumpPrinciples of Operationmotor on and commands the HCU to open and

ABS with Traction Control, Electronic close the appropriate solenoid valves to modulateStability Control (ESC) and Roll Stability the brake pressure to the brake caliper(s) whileControl (RSC) simultaneously sending a request to the PCM over

the high-speed controller area network (HS-CAN)The ABS module with traction control and rollbus to reduce engine torque to maintain vehiclestability control (RSC) manages anti-lock braking totraction. The PCM accomplishes this by minormaintain vehicle control during deceleration andincremental timing changes and fewer fuel injectorperforms additional functions specific to tractionpulses until the ABS module ends the request. Thecontrol and RSC.request ends when the driven wheel speed returns tothe desired speed. After the vehicle speed exceeds100 km/h (62 mph), the traction control isaccomplished only through the PCM torque control.The traction control system can be deactivated bypressing the stability/traction control switch in theinstrument panel.

Copyright 2007, Ford Motor CompanyLast updated: 8/12/2008 2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)

Roll Stability Control (RSC)When the traction control system activates, any ofThe roll stability control (RSC) system constantlythe following can occur:monitors the vehicle motion relative to the intended

• A small deceleration or a reduction in the course. This is done by using sensors to compareacceleration of the vehicle the steering input and brake application with that of

• The traction control indicator in the instrument the actual vehicle motion. The system does notcluster flashes activate when the vehicle is traveling in reverse;

however, the standard ABS and traction control• If the driver’s foot is on the brake pedal, acontinue to function as usual. The RSC systemvibration will be felt in the pedal much like ABSmonitors information from the wheel speed sensors,

Electronic Stability Control (ESC) the throttle position sensor, the steering wheelThe electronic stability control (ESC) system rotation sensor (steering wheel angle and rate ofconstantly monitors the vehicle motion relative to change) and a roll-rate sensor (integral to thethe intended course. This is done by using sensors stability control sensor cluster) that measuresto compare the steering input and the yaw rate changes in vehicle motion. If the RSC systemsensor with that of the actual vehicle motion. The determines from all these inputs that conditionsESC system monitors information from the throttle exist for a potential roll-over event, the systemposition (TP) sensor, the steering wheel rotation adjusts the brake torque at specific wheels insensor (steering wheel angle and rate of change) and response to direct measurement of the vehicle rolla yaw rate sensor (integral to the stability control motion and reduces engine torque to make thesensor cluster) that measures changes in vehicle vehicle more stable. By adjusting brake torque, thedirection. If the ESC system determines from all system can reduce the cornering forces and,these inputs that the vehicle is unable to travel in therefore, the total roll moment acting on thethe intended direction, the system adjusts the brake vehicle. The RSC system can be deactivated bytorque at specific wheels in response to direct pressing the stability/traction control switch in themeasurement of the vehicle motion and reduces instrument panel.engine torque to allow the vehicle to follow the

When the RSC system activates, any of theintended course. The ESC system can be deactivatedfollowing can occur:by pressing the stability/traction control switch in

the instrument panel. • A rumble or grinding sound much like ABS ortraction controlWhen the ESC system activates, any of the

following can occur: • A small deceleration or a reduction in theacceleration of the vehicle• A rumble or grinding sound much like ABS or

• The RSC indicator flashestraction control• If the driver’s foot is on the brake pedal, a• A small deceleration or a reduction in the

vibration will be felt in the pedal much like ABSacceleration of the vehicleSome drivers may notice a slight movement of the• The roll stability control (RSC) indicator flashesbrake pedal when the system checks itself. The• If the driver’s foot is on the brake pedal, abrake pedal moves when an active test of the brakevibration will be felt in the pedal much like ABSbooster is run. During this test a small amount ofpressure is generated at the master cylinder, but nopressure is generated in the brake calipers.

Stability/Traction Control SwitchThe stability/traction control switch is hard-wired tothe instrument cluster module. The instrumentcluster module communicates the stability/tractioncontrol switch status to the ABS module via theHS-CAN bus.

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The stability/traction control switch allows the The yaw rate sensor measures the relative vehicledriver to control use of the ESC/RSC and traction motion about the vertical axis through its center ofcontrol system. This is independent of the ABS gravity.function, which cannot be switched OFF by the The roll rate sensor measures the rate of rotationdriver. The ESC/RSC and traction control system along the front to rear horizontal axis.status is indicated by a light in the stability/tractioncontrol switch. When the stability/traction control Steering Wheel Rotation Sensorswitch is set to OFF, the system is disabled at and The steering wheel rotation sensor measures the ratebelow 32 km/h (20 mph). The system will of rotation of the steering wheel by monitoring theautomatically restore to full functionality every steering wheel rotation ring as it passes through thetime the vehicle speed exceeds 32 km/h (20 mph) or sensor gap. The steering wheel rotation sensor useswhen the ignition switch is cycled from OFF to 2 signal lines to transmit information to the ABSRUN. However, the stability/traction control switch module about whether the steering wheel is beingOFF indicator remains illuminated until the switch turned left or right and how far it is being turned.is pressed a second time. The ABS function The steering wheel rotation sensor does not indicatecontinues to work as designed unless the yellow the absolute position of the steering wheel relativeABS warning indicator is illuminated. Normal to straight-ahead. The stability assist system learnsbraking function always occurs, unless the red brake this position by comparing the steering wheelwarning indicator is illuminated. position with other signals and storing the position

it has learned. The stability assist system confirmsElectronic Brake Distribution (EBD)this position and modifies it as necessary during

The HCU is used as an electronic proportioning every new driving cycle.valve for electronic brake distribution (EBD). TheHCU controls the brake fluid pressure to the rear ABS Module Calibrationbrakes to prevent them from applying before the If installing a new ABS module, HCU, steeringfront brakes. If ABS is disabled due to DTCs being wheel rotation sensor or stability control sensorpresent in the ABS module, EBD will also be cluster, the calibration procedure must be carrieddisabled. Instrument cluster failure or a missing out. The calibration procedure is required for theinstrument cluster message on the HS-CAN bus will ABS module to learn the ‘‘zero-position’’ of thealso disable EBD. various ESC/RSC sensors and components.

To calibrate the ABS module, connect the scan toolStability Control Sensor Clusterand carry out the Interactive Vehicle DynamicsThe sensor cluster (also called inertial module)(IVD) Initialization sequence.consists of the yaw rate sensor, roll rate sensor,If a DTC is logged for any component of thelateral accelerometer and longitudinal accelerometer.ESC/RSC system, the DTC must be cleared orThe lateral accelerometer measures the accelerationrepaired before carrying out the initializationwhich corresponds to the force involved when thesequence. The need to calibrate the ABS module isvehicle slides sideways. This acceleration has 2also indicated by the RSC indicator on theforms. The first is the centrifugal acceleration whichinstrument cluster module flashing once every 2is generated when the vehicle travels around in aseconds. The indicator flashes after clearing thecircle. The second is the acceleration due to gravity.DTCs that are associated with the RSC system. If aOn level ground there is no contribution from thisDTC is retrieved after calibration, refer to the ABSacceleration. However, if the vehicle is parkedModule DTC Chart in this section.sideways on a bank or incline, the sensor measures

some lateral acceleration due to gravity even though When carrying out the initialization sequence for thethe vehicle is not moving. ABS module, the vehicle must be on a level

surface, must not be moving and the ignition switchThe longitudinal accelerometer measures themust be in the RUN position.acceleration corresponding to the force involved

when the vehicle moves forward and rearward inthe horizontal plane, along the centerline of thevehicle’s front and rear wheels.

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Visual Inspection ChartWhen carrying out the initialization sequence for theABS module after installing a new steering wheel Mechanical Electricalrotation sensor, the ignition switch must be in the

• Base brake system • ABS moduleRUN position with the engine running and the • Hydraulic control unit • Battery junction boxsteering wheel must be rotated back and forth from (HCU) (BJB) fuse(s):lock position to lock position. • Steering wheel rotation — 11 (40A)

sensor ring — 16 (40A)Inspection and Verification • Tire pressure • Brake pedal position

• Tire size or mismatched (BPP) switchIdentifying the Brake System tires • Central junction box

• Wheel speed sensor ring (CJB) fuse(s):Two ABS systems are available for this vehicle: — 2 (10A)standard ABS and ABS enhanced with traction — 22 (15A)control and stability assist. ABS with traction • Stability control sensor

clustercontrol and stability assist may also be called• Stability/traction controlelectronic stability control (ESC), roll stability

switchcontrol (RSC), AdvanceTrac, or interactive vehicle• Steering wheel rotation

dynamics (IVD) by the scan tool and other service sensorpublications. • Traction control switch

• Wheel speed sensorVehicles that are equipped with traction control and• Wiring, terminals orstability assist can be identified by the presence of connectors

individual left and right rear wheel speed sensors.

Vehicles with standard ABS can be identified by the5. If an obvious cause for an observed or reportedabsence of rear wheel speed sensors.

concern is found, correct the cause (if possible)If the vehicle is equipped with standard ABS, refer before proceeding to the next step.to Anti-Lock Control in this section to continue

6. NOTE: Make sure to use the latest scan tooldiagnosis of this system.software release.

1. Verify the customer concern.If the cause is not visually evident, connect the

2. Verify the stop lamps operate correctly by scan tool to the data link connector (DLC).pressing and releasing the brake pedal with the

7. NOTE: The vehicle communication moduleignition switch in the OFF position. If the(VCM) LED prove out confirms power andstoplamps do not operate correctly, refer toground from the DLC are provided to theSection 417-01. If the stoplamps operateVCM.correctly, proceed to the next step.If the scan tool does not communicate with the3. Verify the base brake system operates correctly.VCM:If any concerns are present, address them before• check the VCM connection to the vehicle.continuing with any ABS concerns. Refer to

Section 206-00. If the base brake system • check the scan tool connection to the VCM.operates correctly, proceed to the next step. • refer to Section 418-00, No Power To The

4. Visually inspect for obvious signs of Scan Tool, to diagnose no communicationmechanical or electrical damage. with the scan tool.

8. If the scan tool does not communicate with thevehicle:

• verify the ignition key is in the ON position.

• verify the scan tool operation with a knowngood vehicle.

• refer to Section 418-00 to diagnose noresponse from the PCM.

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9. Carry out the network test. 11. If the DTCs retrieved are related to the concern,go to the ABS Module DTC Chart or the• If the scan tool responds with noInstrument Cluster DTC Chart. For all othercommunication for one or more modules,DTCs, refer to Section 419-10.refer to Section 418-00.

12. If no DTCs related to the concern are retrieved,• If the network test passes, retrieve andGO to Symptom Chart.record continuous memory DTCs.

10. Clear the continuous DTCs and carry out theself-test diagnostics for the ABS module andthe instrument cluster.

ABS Module DTC Chart

DTC Description Source Action

B1104 Steering Angle Sensor Signal Error ABS Module GO to Pinpoint Test K.

B1317 Battery Voltage High ABS Module GO to Pinpoint Test G.

B1318 Battery Voltage Low ABS Module GO to Pinpoint Test G.

NOTE:B1342 ECU is Faulted ABS ModuleIf other DTCs are present, REPAIR thembefore installing a new component.

CLEAR the DTCs. CARRY OUT theself-test and RETRIEVE the DTCs. IfDTC is retrieved again, INSTALL a newABS module. REFER to Anti-LockBrake System (ABS) Module in thissection. Using the scan tool, CARRYOUT the IVD Initialization sequence.CLEAR the DTCs. CARRY OUT theself-test with the brake pedal not applied.

B211B Satellite ECU (Stability Control Sensor ABS Module CHECK the stability control sensorCluster) is Faulted cluster electrical connector and wiring for

water intrusion. REPAIR as necessary. IfOK, INSTALL a new sensor cluster.REFER to Stability Control SensorCluster in this section. CLEAR theDTCs. CARRY OUT the self-test withthe brake pedal not applied.

B2900 VIN Mismatch ABS Module GO to Pinpoint Test R.

C1095 ABS Hydraulic Pump Motor Circuit ABS Module GO to Pinpoint Test H.Failure

C1096 ABS Hydraulic Pump Motor Circuit ABS Module GO to Pinpoint Test H.Open

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ABS Module DTC Chart (Continued)


NOTE:C1115 ABS Power Relay Output Short Circuit ABS ModuleIf other DTCs are present, REPAIR themto Batterybefore installing a new component.

CLEAR all DTCs. TEST DRIVE thevehicle above 32 km/h (20 mph) andCARRY OUT at least one ABS stop.RETRIEVE the DTCs.If DTC C1115 is retrieved again,INSTALL a new ABS module. REFERto Anti-Lock Brake System (ABS)Module in this section. Using the scantool, CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

C1145 RF Wheel Speed Sensor Input Circuit ABS Module GO to Pinpoint Test I.Failure

C1155 LF Wheel Speed Sensor Input Circuit ABS Module GO to Pinpoint Test I.Failure

C1165 RR Wheel Speed Sensor Input Circuit ABS Module GO to Pinpoint Test I.Failure

C1175 LR Wheel Speed Sensor Input Circuit ABS Module GO to Pinpoint Test I.Failure

NOTE:C1185 ABS Power Relay Output Circuit Failure ABS ModuleREPAIR all other DTCs prior todiagnosing this one.

CLEAR all DTCs. RETRIEVE DTCs. Ifthe DTC is retrieve again, INSTALL anew ABS module. REFER to Anti-LockBrake System (ABS) Module in thissection. Using the scan tool, CARRYOUT the IVD Initialization sequence.CLEAR the DTCs. CARRY OUT theself-test with the brake pedal not applied.

C1194 ABS Outlet Valve Coil LF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Failure RETRIEVE the DTCs. If multiple coil

DTCs are retrieved, GO to Pinpoint TestG. If only DTC C1194 is retrieved,INSTALL a new ABS module. REFERto Anti-Lock Brake System (ABS)Module in this section. Using the scantool, CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

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C1198 ABS Inlet Valve Coil LF Circuit Failure ABS Module CLEAR all DTCs. DRIVE the vehicle.RETRIEVE the DTCs. If multiple coilDTCs are retrieved, GO to Pinpoint TestG. If only DTC C1198 is retrieved,INSTALL a new ABS module. REFERto Anti-Lock Brake System (ABS)Module in this section. Using the scantool, CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

C1210 ABS Outlet Valve Coil RF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Failure RETRIEVE the DTCs. If multiple coil


C1214 ABS Inlet Valve Coil RF Circuit Failure ABS Module CLEAR all DTCs. DRIVE the vehicle.RETRIEVE the DTCs. If multiple coilDTCs are retrieved, GO to Pinpoint TestG. If only DTC C1214 is retrieved,INSTALL a new ABS module. REFERto Anti-Lock Brake System (ABS)Module in this section. Using the scantool, CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

C1222 Wheel Speed Mismatch ABS Module GO to Pinpoint Test J.

C1233 LF Wheel Speed Input Signal Missing ABS Module GO to Pinpoint Test J.

C1234 RF Wheel Speed Input Signal Missing ABS Module GO to Pinpoint Test J.

C1235 RR Wheel Speed Input Signal Missing ABS Module GO to Pinpoint Test J.

C1236 LR Wheel Speed Input Signal Missing ABS Module GO to Pinpoint Test J.

C1242 ABS Outlet Valve Coil LR Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Failure RETRIEVE the DTCs. If multiple coil


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C1246 ABS Outlet Valve Coil RR Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Failure RETRIEVE the DTCs. If multiple coil


C1250 ABS Inlet Valve Coil LR Circuit Failure ABS Module CLEAR all DTCs. DRIVE the vehicle.RETRIEVE the DTCs. If multiple coilDTCs are retrieved, GO to Pinpoint TestG. If only DTC C1250 is retrieved,INSTALL a new ABS module. REFERto Anti-Lock Brake System (ABS)Module in this section. Using the scantool, CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

C1254 ABS Inlet Valve Coil RR Circuit Failure ABS Module CLEAR all DTCs. DRIVE the vehicle.RETRIEVE the DTCs. If multiple coilDTCs are retrieved, GO to Pinpoint TestG. If only DTC C1254 is retrieved,INSTALL a new ABS module. REFERto Anti-Lock Brake System (ABS)Module in this section. Using the scantool, CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

C1277 Steering Wheel Angle 1 and 2 Circuit ABS Module GO to Pinpoint Test K.Failure

C1278 Steering Wheel Angle 1 and 2 Signal ABS Module GO to Pinpoint Test K.Faulted

C1279 Yaw Rate Sensor Circuit Failure ABS Module GO to Pinpoint Test L.

C1280 Yaw Rate Sensor Signal Fault ABS Module GO to Pinpoint Test L.

C1281 Lateral Accelerometer Circuit Failure ABS Module GO to Pinpoint Test L.

C1282 Lateral Accelerometer Signal Fault ABS Module GO to Pinpoint Test L.

C1288 Pressure Transducer Main/Primary Input ABS Module GO to Pinpoint Test M.Circuit Failure

C1329 ABS Outlet Valve Coil RF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is

retrieved again, INSTALL a new ABSmodule. REFER to Anti-Lock BrakeSystem (ABS) Module in this section.Using the scan tool, CARRY OUT theIVD Initialization sequence. CLEAR theDTCs. CARRY OUT the self-test withthe brake pedal not applied.

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C1330 ABS Outlet Valve Coil LR Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1331 ABS Outlet Valve Coil RR Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1332 ABS Outlet Valve Coil LF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1333 ABS Inlet Valve Coil LR Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1334 ABS Inlet Valve Coil LF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1335 ABS Inlet Valve Coil RF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


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C1336 ABS Inlet Valve Coil RR Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1404 Traction Control Valve Rear Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Failure RETRIEVE the DTCs. If multiple coil


C1410 Traction Control Valve LF Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Failure RETRIEVE the DTCs. If multiple coil


C1446 Base Brake Failure/Brake Switch Stuck ABS Module GO to Pinpoint Test N.or Inoperative

C1516 Roll Rate Sensor Signal Fault ABS Module GO to Pinpoint Test L.

C1517 Roll Rate Sensor Circuit Fault ABS Module GO to Pinpoint Test L.

C1527 Traction Control Rear Valve Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1528 Traction Control LF Valve Circuit ABS Module CLEAR all DTCs. DRIVE the vehicle.Excessive Temperature RETRIEVE the DTCs. If the DTC is


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C1530 Dynamic Stability Control RF Valve ABS Module CLEAR all DTCs. DRIVE the vehicle.Circuit Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1531 Dynamic Stability Control LF Valve ABS Module CLEAR all DTCs. DRIVE the vehicle.Circuit Excessive Temperature RETRIEVE the DTCs. If the DTC is


C1730 Reference Voltage Out of Range (+5 V) ABS Module If any other DTCs are present, diagnosethose DTCs first. CLEAR all DTCs.DRIVE the vehicle. RETRIEVE DTCs.If the DTC is retrieved again, INSTALLa new ABS module. REFER toAnti-Lock Brake System (ABS) Modulein this section. Using the scan tool,CARRY OUT the IVD Initializationsequence. CLEAR the DTCs. CARRYOUT the self-test with the brake pedalnot applied.

C1957 Dynamic Stability Control Valve RF ABS Module CLEAR all DTCs. DRIVE the vehicle.Circuit Failure RETRIEVE the DTCs. If multiple coil


C1958 Dynamic Stability Control Valve LF ABS Module CLEAR all DTCs. DRIVE the vehicle.Circuit Failure RETRIEVE the DTCs. If multiple coil


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NOTE:C1963 Stability Control Inhibit Warning ABS ModuleThis DTC will not clear until the vehiclehas been driven above 48 km/h (30 mph)with input from the steering wheelrotation sensor.

REPAIR all other DTCs before repairingDTC C1963. GO to Pinpoint Test K.

NOTE:C1991 Module Calibration Failure ABS ModuleREPAIR all other DTCs prior todiagnosing this DTC.

GO to Pinpoint Test O.

C2769 Longitudinal Acceleration Sensor ABS Module GO to Pinpoint Test L.Electrical Failure

C2770 Longitudinal Acceleration Sensor ABS Module GO to Pinpoint Test L.Plausibility Failure

U0028 Vehicle Communication Bus Off ABS Module GO to Pinpoint Test L.

U0073 Control Module Communication Bus Off ABS Module REFER to Section 418-00 to diagnosethe high-speed controller area network(HS-CAN) bus.

U0115 Lost Communication with ECM/PCM - ABS Module REPAIR all other DTCs first. If DTCSecondary U0115 is still present REFER to Section

418-00 to diagnose the HS-CAN bus.

U0155 Lost Communication with Instrument ABS Module REPAIR all other DTCs first. If DTCPanel Cluster U0155 is still present REFER to Section

418-00 to diagnose the HS-CAN bus.

U2050 No Application Present ABS Module CLEAR the DTCs. REPEAT theself-test. RETRIEVE the DTCs. If DTCU2050 is retrieved again, INSTALL anew ABS module. REFER to Anti-LockBrake System (ABS) Module in thissection. Using the scan tool, CARRYOUT the IVD Initialization sequence.CLEAR the DTC. REPEAT the self-test.

U2051 One or More Calibration Files ABS Module CLEAR the DTCs. CARRY OUT theMissing/Corrupt ABS module self-test. RETRIEVE and

RECORD any DTCs. If DTC U2051 isretrieved again, INSTALL a new ABSmodule. REFER to Anti-Lock BrakeSystem (ABS) Module in this section.Using the scan tool, CARRY OUT theIVD Initialization sequence. CLEAR theDTC. REPEAT the self-test.

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Instrument Cluster DTC Chart


C1093 Traction Control Disable Switch Circuit Instrument GO to Pinpoint Test P.Failure Cluster

C1105 Traction Control Disable Lamp Circuit Instrument GO to Pinpoint Test Q.Short to Battery Cluster

— All Other instrument cluster DTCs Instrument REFER to the Master DTC Chart inCluster Section 419-10.

Symptom Chart

Symptom Chart

Condition Possible Sources Action• The red BRAKE warning • DTCs present in the ABS • REFER to the ABS Module

indicator and the yellow ABS module DTC Chart in this section.warning indicator are bothilluminated

• The ABS warning indicator is • Wiring, terminals or • REFER to Section 413-01 tonever on connectors continue diagnosis of the

• Instrument cluster warning indicator.• The red BRAKE warning • Wiring, terminals or • REFER to Section 413-01 to

indicator is always/never on connectors continue diagnosis of the• Parking brake switch warning indicator.• Brake fluid level switch (part

of the master cylinder)• Brake fluid level• Instrument cluster

• The stability/traction control • DTCs present in the ABS • RETRIEVE and RECORDindicator (in the instrument module or PCM any ABS module DTCs. GOcluster) is always/never on • PCM to the ABS Module DTC

• Instrument cluster Chart. If there are no DTCspresent in the ABS module,RETRIEVE and RECORDany PCM DTCs. REFER tothe PowertrainControl/Emissions Diagnosis(PC/ED) manual. If there areno PCM DTCs, REFER toDiagnosis and Testing inSection 413-01.

• The stability/traction control • Wiring, terminals or • GO to Pinpoint Test Q.OFF indicator (in the switch) connectorsis always/never on • Stability/traction control

switch• PCM

• The stability/traction control • NOTE: It is normal for the • RETRIEVE and RECORD allindicator (in the instrument indicator to flash during a ABS module DTCs and GOcluster) is flashing at all times traction control event. to the ABS Module DTC

Chart.ABS module not configuredor system not initialized

• No communication with the • Wiring, terminals or • REFER to Section 418-00 toABS module connectors diagnose the no

• ABS module communication concern.

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Symptom Chart (Continued)

Condition Possible Sources Action• The stability/traction control • Fuse • GO to Pinpoint Test P.

system cannot be • Wiring, terminals ordisabled/enabled connectors

• Stability/traction controlswitch

• PCM• The stability/traction control • Stability/traction control • GO to Pinpoint Test P.

system is inoperative system is turned off• Stability/traction control

system is not configured• Fuse• Wiring, terminals or

connectors• ABS wheel speed sensor fault• High-speed controller area

network (HS-CAN) bus fault• PCM

• ABS false activation, ABS • Brake pads • ELIMINATE the base braketoo sensitive, ABS activates • Brake calipers and/or guide system as the cause of theon a normal stop pins problem. REFER to Diagnosis

and Testing in Section206-00.

• Parking brake shoes out of • CHECK and if necessary,adjustment (dragging) ADJUST the parking brake

shoes. REFER to Section206-05.

• Wheel speed sensor tone • INSPECT the wheel speedrings sensor tone rings for damaged

teeth and excessive air gap.INSTALL new wheel speedsensor rings as necessary. Forfront tone rings, REFER toWheel Speed Sensor Ring —Front in this section. For reartone rings, REFER to WheelHub Removal and Installationin Section 205-02B.

• Wheel speed sensor • GO to Pinpoint Test J.• Chafed wheel speed sensor • INSPECT the wiring harness

wire insulation or pinched from the wheel speed sensorwheel speed sensor wire knuckle to the frame and

from the rear axle to theframe. REPAIR as necessary.

• Open or shorted wheel speed • GO to Pinpoint Test I.sensor circuit

• Vehicle pulls during braking • Brake pads • DISCONNECT the ABS• Brake discs module electrical connector.• Brake calipers and/or guide DRIVE the vehicle and

pins VERIFY the condition. If the• Wheel speed sensor condition is still present,

REFER to Section 206-00 todiagnose the base brakingsystem. If the condition is nolonger present, GO toPinpoint Test J.

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Symptom Chart (Continued)

Condition Possible Sources Action• Wheels lock up • Brake pads • ELIMINATE the base brake

• Brake calipers and/or guide system as the cause of thepins problem. REFER to Diagnosis

and Testing in Section206-00.

• Parking brake shoes out of • CHECK and if necessary,adjustment (dragging) ADJUST the parking brake

shoes. REFER to Section206-05.

• Hydraulic outlet (dump) valve • BLEED the HCU. REFER to• Leaky inlet (isolation) valve Brake System Bleeding in

during ABS (soft) Section 206-00. TEST thesystem for normal operation.If the symptom returns,INSTALL a new HCU.REFER to Hydraulic ControlUnit (HCU) in this section.Using the scan tool, CARRYOUT the IVD Initializationsequence. TEST the systemfor normal operation.

• Soft/excessive brake pedal • Air in brake system • ELIMINATE the base braketravel • Brake calipers and/or guide system as the cause of the

pins problem. REFER to Diagnosis• Brake flexible hose and Testing in Section• Brake master cylinder 206-00.• Brake pads• Brake pedal• Inlet (isolation) valve or • BLEED the hydraulic control

hydraulic outlet (dump) valve unit (HCU). REFER to Brake• Leaky inlet (isolation) valve System Bleeding in Section

during ABS applications 206-00. TEST the system for(soft) normal operation. If the

symptom returns, INSTALL anew HCU. REFER toHydraulic Control Unit(HCU) in this section. Usingthe scan tool, CARRY OUTthe IVD Initializationsequence. TEST the systemfor normal operation.

Pinpoint Tests A low or weak battery or a weak charging systemwill cause the DTCs to set. Make sure the battery is

Pinpoint Test G: DTCs B1317 and B1318 — operating at a minimum of 10 volts and that theBattery Voltage High/Low charging system is fully operational.Refer to Wiring Diagrams Cell 42, VehicleDynamic Systems for schematic and connectorinformation.

Normal OperationThe operating voltage range for the ABS and theroll stability control (RSC) system is 10-16 volts.

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Fused battery voltage for hydraulic pump motor NOTE: Circuit 494 (TN/LG) passes through theoperation is supplied to the ABS module from wire assembly jumper connected to ABS factory testbattery junction box (BJB) fuse 11 (40A) along connector C126. If a fault is present on circuit 494circuit 532 (OG/YE). Fused battery voltage for (TN/LG), make sure to check for an open betweenhydraulic valve and coil operation is supplied to pin-4 and pin-12 of the wire assembly jumper.ABS test connector C126 from BJB fuse 16 (40A)along circuit 494 (TN/LG), the voltage passesthrough the test connector and continues to the ABSmodule along circuit 493 (PK/BK). Fused ignitionvoltage is supplied to ABS test connector C126central junction box (CJB) fuse 2 (10A) alongcircuit 640 (RD/YE), the voltage passes through thetest connector and continues to the ABS modulealong circuit 640 (RD/YE). Ground for the ABSmodule is provided along circuit 530 (LG/YE).

DTC Description Fault Trigger Conditions

• DTC B1317 Battery Voltage High If the voltage supplied to the ABS module exceeds 16volts during the ABS module self-test or normaloperation, with vehicle speed greater than 5 km/h (3mph), DTC B1317 will be set.

• DTC B1318 Battery Voltage Low If the voltage supplied to the ABS module falls below 10volts during the ABS module self-test or normaloperation, with vehicle speed greater than 5 km/h (3mph), DTC B1318 will be set.

• DTC C1194 ABS Outlet Valve Coil LF Circuit Failure If during normal operation or the on-demand self test the• DTC C1198 ABS Inlet Valve Coil LF Circuit Failure ABS module detects an open circuit, short to ground or• DTC C1210 ABS Outlet Valve Coil RF Circuit Failure battery, or a defective trigger circuit, the appropriate DTC• DTC C1214 ABS Inlet Valve Coil RF Circuit Failure will be set.• DTC C1242 ABS Outlet Valve Coil LR Circuit Failure• DTC C1246 ABS Outlet Valve Coil RR Circuit Failure• DTC C1250 ABS Inlet Valve Coil LR Circuit Failure• DTC C1254 ABS Inlet Valve Coil RR Circuit Failure• DTC C1404 Traction Control Valve Rear Circuit

Failure• DTC C1410 Traction Control Valve LF Circuit Failure• DTC C1957 Dynamic Stability Control Valve RF

Circuit Failure• DTC C1958 Dynamic Stability Control Valve LF

Circuit Failure

This pinpoint test is intended to diagnose the following:

• Wiring, terminals or connectors

• Vehicle charging system

• ABS module

PINPOINT TEST G: DTCs B1317 AND B1318 — BATTERY VOLTAGE HIGH/LOW

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiringterminals. Do not use standard multi-meter probes.

Test Step Result / Action to TakeG1 CHECK FOR RETURNING DTCs

• Connect the scan tool. Yes• Ignition ON. GO to G2.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST G: DTCs B1317 AND B1318 — BATTERY VOLTAGE HIGH/LOW (Continued)

Test Step Result / Action to TakeG1 CHECK FOR RETURNING DTCs (Continued)

• Clear the DTCs and carry out the ABS module self-test. No• Retrieve and record any ABS module DTCs. For all other DTCs, GO to the ABS• Do any of the DTCs listed in Normal Operation return? Module DTC Chart.G2 CHECK THE BATTERY VOLTAGE

• Measure the voltage between the positive and negative battery Yesterminals with the key ON and the engine OFF (KOEO), and GO to G3.with the engine running. No• Is the battery voltage between 10 and 13 volts with KOEO, INSPECT the ABS module electricaland between 13 and 17 volts with the engine running? connector for corrosion, pushed-out pins

and spread terminals.If OK, REFER to Section 414-00 tocontinue diagnosis of the charging system.If not OK, REPAIR as necessary. CLEARthe DTCs and CARRY OUT the self-testwith the brake pedal not applied.

G3 CHECK THE VOLTAGE TO THE ABS TEST CONNECTOR• Ignition OFF.• Disconnect: ABS Test Connector C126.• Ignition ON.• Measure the voltage between ground and:

— ABS test connector C126-4, circuit 494 (TN/LG), harnessside.

— ABS test connector C126-6, circuit 640 (RD/YE), harnessside.

YesGO to G4.NoVERIFY BJB fuse 16 (40A) and CJB fuse2 (10A) are OK. If OK, REPAIR theaffected circuit(s). CLEAR the DTCs.

• Are the voltages greater 10 volts? REPEAT the self-test.G4 CHECK THE VOLTAGE TO THE ABS MODULE

NOTE: Circuits 494 (TN/LG) and 640 (RD/YE) pass through thejumper harness connected to ABS test connector C126. If there is afault in one or both of these circuits, check the jumper harness foran open.• Ignition OFF.• Connect: ABS Test Connector C126.• Disconnect: ABS Module C155.• Ignition ON.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST G: DTCs B1317 AND B1318 — BATTERY VOLTAGE HIGH/LOW (Continued)

Test Step Result / Action to TakeG4 CHECK THE VOLTAGE TO THE ABS MODULE (Continued)

• Measure the voltage between ground and:— ABS module C155-2, circuit 493 (PK/BK), harness side.— ABS module C155-31, circuit 532 (OG/YE), harness side.— ABS module C155-32, circuit 640 (RD/YE), harness side.

YesGO to G5.NoIf the voltages at pin-2 and/or pin-32 arenot greater than 10 volts, VERIFY thejumper harness for the ABS test connectoris OK. If OK, REPAIR the affectedcircuit(s). CLEAR the DTCs. REPEAT theself-test.If the voltage at pin-31 is not greater than10 volts, VERIFY BJB fuse 11 (40A) isOK. If OK, REPAIR circuit 532 (OG/YE).

• Are the voltages greater than 10 volts? CLEAR the DTCs. REPEAT the self-test.G5 CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN

• Ignition OFF.• Measure the resistance between ground and:

— ABS module C155-16, circuit 530 (LG/YE), harness side.— ABS module C155-45, circuit 530 (LG/YE), harness side.

YesGO to G6.NoREPAIR circuit 530 (LG/YE). CLEAR the

• Are the resistances less than 5 ohms? DTCs. REPEAT the self-test.G6 CHECK FOR CORRECT ABS MODULE OPERATION

• Check ABS module C155 for: YesINSTALL a new ABS module. REFER to— corrosion. Anti-Lock Brake System (ABS) Module in— pushed-out pins. this section. Using the scan tool, CARRY— spread terminals. OUT the IVD Initialization sequence.• Connect: ABS Module C155. CLEAR the DTCs. CARRY OUT the• Make sure the connector is fully seated and locked, then self-test with the brake pedal not applied.operate the system and verify the concern is still present.

• Is the concern still present? NoThe system is operating correctly at thistime. The concern may have been causedby a loose or corroded connector or amalfunctioning charging system. CLEARthe DTCs. CARRY OUT the self-test withthe brake pedal not applied.

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Pinpoint Test H: DTCs C1095 and C1096 — • DTC C1096 ABS Hydraulic Pump Motor CircuitABS Hydraulic Pump Motor Circuit Open — If a short to voltage, a short to groundFailure/Open or an open is detected, if a locked up pump motor

is detected or if there is an internal failure of theRefer to Wiring Diagrams Cell 42, VehicleABS module, DTC C1095 will be set.Dynamic Systems for schematic and connector

information. This pinpoint test is intended to diagnosethe following:Normal Operation

Fused battery voltage for hydraulic pump motor • Fuseoperation is supplied to the ABS module by battery • Wiring, terminals or connectorsjunction box (BJB) fuse 11 (40A) along circuit 532

• Hydraulic pump motor(OG/YE). Ground is provided to the ABS module• ABS modulealong circuit 530 (LG/YE).

When the ignition key is turned to the ON position,the ABS module commands the hydraulic controlunit (HCU) pump on for 100 ms (+/-6 ms) and isthen commanded off. After 6 ms, the ABS modulewill read the voltage that is being generated by theHCU pump. If the voltage indicates the motor isspinning at less than 500 rpm, there may be alocked motor. If this condition is detected 4 times,DTC C1095 is set. The pump motor is checked foran open circuit 2 seconds after the most recentsuccessful pump motor off command. If the pumpmotor feedback remains greater than 0.75 volt formore than 50 ms (+/-6 ms) after these conditionshave been met, DTC C1096 is set.

• DTC C1095 ABS Hydraulic Pump Motor CircuitFailure — If a short to voltage or ground isdetected, if a locked up pump motor is detected orif there is an internal failure of the ABS module,DTC C1095 will be set.

PINPOINT TEST H: DTCs C1095 AND C1096 — ABS HYDRAULIC PUMP MOTOR CIRCUITFAILURE/OPEN


Test Step Result / Action to TakeH1 CHECK FOR ABS MODULE DTCs

• Connect the scan tool.• Ignition ON.• Using the scan tool, clear all ABS module DTCs.• Ignition OFF. Yes• Ignition ON. GO to H2.• Enter the following diagnostic mode on the scan tool: Self Test

ABS Module. No• Retrieve and record all ABS module DTCs. For all other DTCs, GO to the ABS• Are DTCs C1095 or C1096 present? Module DTC Chart.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST H: DTCs C1095 AND C1096 — ABS HYDRAULIC PUMP MOTOR CIRCUIT

FAILURE/OPEN (Continued)

Test Step Result / Action to TakeH2 CHECK THE ABS PUMP MOTOR

• Ignition ON. Yes• Is the ABS pump motor running all the time? INSTALL a new ABS module and

hydraulic control unit (HCU). REFER toAnti-Lock Brake System (ABS) Moduleand Hydraulic Control Unit (HCU) in thissection. Using the scan tool, CARRYOUT the IVD Initialization sequence.CLEAR the DTCs. REPEAT the self-test.NoGO to H3.

H3 CHECK FOR RETURNING ABS MODULE DTCs• Connect the scan tool. Yes• Ignition ON. If DTC C1096 is retrieved, GO to H6.• Enter the following diagnostic mode on the scan tool: ABS If DTC C1095 is retrieved, GO to H4.

Module DTCs.For all other ABS module DTCs, GO to• Retrieve and record the ABS module DTCs.the ABS Module DTC Chart.• Are any DTCs present?NoThe system is operating correctly at thistime. The concern may have been causedby a loose or corroded connector. CLEARthe DTCs. CARRY OUT the self-test withthe brake pedal not applied.

H4 CHECK THE VOLTAGE TO THE ABS MODULE• Ignition OFF.• Disconnect: ABS Module C155.• Ignition ON.• Measure the voltage between ABS module C155-31, circuit 532

(OG/YE), harness side and ground.

YesGO to H5.NoVERIFY BJB fuse 11 (40A) is OK. If OK,REPAIR circuit 532 (OG/YE). CLEAR the

• Is the voltage greater than 10 volts? DTCs. REPEAT the self-test.H5 CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN

• Ignition OFF.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST H: DTCs C1095 AND C1096 — ABS HYDRAULIC PUMP MOTOR CIRCUIT

FAILURE/OPEN (Continued)

Test Step Result / Action to TakeH5 CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN

(Continued)

• Measure the resistance between ground and:— ABS module C155-16, circuit 530 (LG/YE), harness side.— ABS module C155-45, circuit 530 (LG/YE), harness side.

YesINSTALL a new HCU. REFER to HydraulicControl Unit (HCU) in this section. Usingthe scan tool, CARRY OUT the IVDInitialization sequence. CLEAR the DTCs.REPEAT the self-test. If DTC C1045returns, GO to H6.NoREPAIR circuit 530 (LG/YE). CLEAR the

• Are the resistances less than 5 ohms? DTCs. REPEAT the self-test.H6 CHECK FOR CORRECT ABS MODULE OPERATION

• Check ABS module C155 for: YesINSTALL a new ABS module. REFER to— corrosion. Anti-Lock Brake System (ABS) Module in— pushed-out pins. this section. Using the scan tool, CARRY— spread terminals. OUT the IVD Initialization sequence.• Connect: ABS Module C155. CLEAR the DTCs. CARRY OUT the• Make sure the connector is fully seated and locked, then self-test with the brake pedal not applied.operate the system and verify the concern is still present.

• Is the concern still present? NoThe system is operating correctly at thistime. The concern may have been causedby a loose or corroded connector or amalfunctioning charging system. CLEARthe DTCs. CARRY OUT the self-test withthe brake pedal not applied.

Pinpoint Test I: ABS False Activation, ABS Wheel speed sensor DTCs will automatically cleartoo Sensitive, ABS Activates On a Normal when a successful test drive is carried out. AStop successful test drive should include speeds above 32

km/h (20 mph) and at least one ABS stop.Normal OperationThe wheel speed sensors are ‘‘active’’ sensors andgenerate a square wave signal that is sent to theABS module. When the ignition is turned to theRUN position, the ABS module carries out aself-test to determine if the sensors are functional.Voltage and ground are supplied to the front wheelspeed sensors from the ABS module along a pair ofwires.

2008 E-Series, 10/2007



DTC Description Fault Trigger Condition

• DTC C1145 RF Wheel Speed Sensor Input Circuit If during the ABS module on-demand self test or duringFailure normal operation, if the ABS module detects an open,

• DTC C1155 LF Wheel Speed Sensor Input Circuit short to ground or voltage or a defective wheel speedFailure sensor input circuit, the appropriate DTC will be set.

• DTC C1165 RR Wheel Speed Sensor Input Circuit These DTCs are usually set by a damaged sensor or aFailure circuit fault.

• DTC C1175 LR Wheel Speed Sensor Input CircuitFailure



• Wheel speed sensor ring

• Wheel speed sensor

• ABS module

PINPOINT TEST I: ABS FALSE ACTIVATION, ABS TOO SENSITIVE, ABS ACTIVATES ON A NORMALSTOP


Test Step Result / Action to TakeI1 CHECK THE ABS HARNESS AND MODULE FOR WATER

INTRUSION• Ignition OFF. Yes• Disconnect: ABS Module C155. CLEAN the connector and dry it out with• Inspect the ABS module connector and module for water low pressure compressed air. INSPECT

intrusion. for evidence of water entry and REPAIR• Is there any evidence of water entry? as necessary. Using the scan tool,

CARRY OUT the IVD Initializationsequence. TEST DRIVE the vehicle above32 km/h (20 mph) and CARRY OUT atleast one ABS stop.NoGO to I2.

I2 CHECK FOR FAULT REPEATABILITY• Connect the scan tool. Yes• Ignition ON. For DTC C1145 or C1155, GO to I5. For• Enter the following diagnostic mode on the scan tool: Clear the DTC C1165 or C1175, if the active wheel

Continuous DTCs. speed sensor tool is available, GO to I3.• Drive the vehicle at least 16 km/h (10 mph). If the active wheel speed sensor tool is• Retrieve and document continuous DTCs. not available, GO to I5.• Is DTC C1145, C1155, C1165 and/or C1175 retrieved?

NoINSPECT the wheel speed sensors, wheelspeed sensor wiring and wheel speedsensor tone rings. REPAIR or INSTALLnew as necessary. If any other DTCs areretrieved, GO to the ABS Module DTCChart.

I3 CHECK THE ABS MODULE OUTPUT USING THE SPECIALTOOL• Ignition OFF.• Disconnect: Suspect Wheel Speed Sensor.• Connect the special tool to the wheel speed sensor connectors. Yes• Ignition ON. GO to I4.• Select the correct system polarity on the special tool and turn

the special tool power switch to the ON position. No• Is the module output LED illuminated? GO to I7.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST I: ABS FALSE ACTIVATION, ABS TOO SENSITIVE, ABS ACTIVATES ON A NORMAL

STOP (Continued)

Test Step Result / Action to TakeI4 CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE

SPECIAL TOOL• Raise the suspect wheel until it can spin freely. Refer to Section Yes

100-02. The system is operating correctly at this• While monitoring the special tool, slowly spin the suspect wheel. time. The concern may have been caused• Do the sensor output LEDs illuminate and flash and is the by a loose or corroded connector. CLEAR

current overload LED not illuminated? the DTCs. REPEAT the self-test.NoIf the current level LED is not illuminatedand the sensor output LEDs do notilluminate or if the current level LED isilluminated red, INSTALL a new wheelspeed sensor. REFER to Wheel SpeedSensor — Front and/or Wheel SpeedSensor — Rear in this section. CLEAR theDTCs. REPEAT the self-test.If the current level LED is not illuminatedand the sensor output LEDs illuminategreen but do not flash, INSPECT thewheel speed sensor tone ring andINSTALL new if necessary. For the fronttone ring, REFER to Wheel SpeedSensor Ring — Front in this section. Forthe rear tone ring, REFER to Brake DiscRemoval and Installation in Section206-04. If the tone ring is OK, INSTALL anew wheel speed sensor, REFER toWheel Speed Sensor — Front and/orWheel Speed Sensor — Rear in thissection. CLEAR the DTCs. REPEAT theself-test.

I5 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORTTO VOLTAGENOTE: Both circuits must be checked for each DTC.• Ignition OFF.• Disconnect: ABS Module C155.• Disconnect: Suspect Wheel Speed Sensor.• Ignition ON.• For DTC C1145 (RF), measure the voltage between ground

and:— ABS module C155-26, circuit 514 (YE/RD), harness side.— ABS module C155-27, circuit 516 (YE/BK), harness side.

• For DTC C1155 (LF), measure the voltage between ground and:— ABS module C155-13, circuit 522 (TN/BK), harness side.— ABS module C155-12, circuit 521 (TN/OG), harness side.

• For DTC C1165 (RR), measure the voltage between groundand: Yes— ABS module C155-44, circuit 524 (PK/BK), harness side. REPAIR the affected circuit(s). TEST— ABS module C155-43, circuit 523 (RD/PK), harness side. DRIVE the vehicle above 32 km/h (20• For DTC C1175 (LR), measure the voltage between ground mph) and CARRY OUT at least one ABSand: stop.— ABS module C155-42, circuit 519 (LG/BK), harness side.— ABS module C155-41, circuit 518 (LG/RD), harness side. No

• Is any voltage present? GO to I6.I6 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT

TO GROUNDNOTE: Both circuits must be checked for each DTC.• Ignition OFF.• For DTC C1145 (RF), measure the resistance between ground

and:— ABS module C155-26, circuit 514 (YE/RD), harness side.— ABS module C155-27, circuit 516 (YE/BK), harness side.

• For DTC C1155 (LF), measure the resistance between groundand:— ABS module C155-13, circuit 522 (TN/BK), harness side.— ABS module C155-12, circuit 521 (TN/OG), harness side.

(Continued)

2008 E-Series, 10/2007



STOP (Continued)

Test Step Result / Action to TakeI6 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT

TO GROUND (Continued)

• For DTC C1165 (RR), measure the resistance between groundand: Yes— ABS module C155-44, circuit 524 (PK/BK), harness side. GO to I7.— ABS module C155-43, circuit 523 (RD/PK), harness side.

• For DTC C1175 (LR), measure the resistance between ground Noand: REPAIR the affected circuit(s). TEST— ABS module C155-42, circuit 519 (LG/BK), harness side. DRIVE the vehicle above 32 km/h (20— ABS module C155-41, circuit 518 (LG/RD), harness side. mph) and CARRY OUT at least one ABS

• Are the resistances greater than 10,000 ohms? stop.I7 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN

NOTE: Both circuits must be checked for each DTC.• Disconnect: ABS Module C155.• Disconnect: Suspect Wheel Speed Sensor.• For DTC C1145 (RF), measure the resistance between:

— ABS module C155-26, circuit 514 (YE/RD), harness sideand RF wheel speed sensor C160-1, circuit 514 (YE/RD),harness side.

— ABS module C155-27, circuit 516 (YE/BK), harness sideand RF wheel speed sensor C160-2, circuit 516 (YE/BK),harness side.

• For DTC C1155 (LF), measure the resistance between:— ABS module C155-13, circuit 522 (TN/BK), harness side

and LF wheel speed sensor C150-2, circuit 522 (TN/BK),harness side.

— ABS module C155-12, circuit 521 (TN/OG), harness sideand LF wheel speed sensor C150-1, circuit 521 (TN/OG),harness side.

• For DTC C1165 (RR), measure the resistance between:— ABS module C155-44, circuit 524 (PK/BK), harness side

and RR wheel speed sensor C426-2, circuit 524 (PK/BK),harness side.

— ABS module C155-43, circuit 523 (RD/PK), harness sideand RR wheel speed sensor C426-1, circuit 523 (RD/PK),harness side.

• For DTC C1175 (LR), measure the resistance between: Yes— ABS module C155-42, circuit 519 (LG/BK), harness side GO to I8.and LR wheel speed sensor C440-1, circuit 519 (LG/BK),harness side. No

— ABS module C155-41, circuit 518 (LG/RD), harness side REPAIR the affected circuit(s). TESTand LR wheel speed sensor C440-2, circuit 518 (LG/RD), DRIVE the vehicle above 32 km/h (20harness side. mph) and CARRY OUT at least one ABS

• Are the resistances less than 5 ohms? stop.I8 CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS

• Measure the resistance between the suspect wheel speed Yessensor pins, harness side. GO to I9.

• Are the resistances greater than 10,000 ohms? NoREPAIR the affected circuit(s). TESTDRIVE the vehicle above 32 km/h (20mph) and CARRY OUT at least one ABSstop.

I9 CHECK THE ABS MODULE OUTPUT• Connect: ABS Module C155. Yes• Ignition ON. INSTALL a new wheel speed sensor.• Measure the voltage between the suspect wheel speed sensor REFER to Wheel Speed Sensor — Front

pins, harness side. and/or Wheel Speed Sensor — Rear in• Is the voltage greater than 10 volts? this section. TEST DRIVE the vehicle

above 32 km/h (20 mph) and CARRYOUT at least one ABS stop.NoGO to I10.

(Continued)

2008 E-Series, 10/2007



STOP (Continued)

Test Step Result / Action to TakeI10 CHECK FOR CORRECT ABS MODULE OPERATION

• Disconnect: ABS Module C155. Yes• Check the connector for: INSTALL a new ABS module. REFER to

Anti-Lock Brake System (ABS) Module in— evidence of water entry into the connector. this section. Using the scan tool, CARRY— corrosion. OUT the IVD Initialization sequence. TEST— pushed-out pins. DRIVE the vehicle above 32 km/h (20— spread terminals. mph) and CARRY OUT at least one ABS• Connect: ABS Module C155. stop.• Make sure the connector is fully seated and locked, thenoperate the system and verify the concern is still present. No

• Is the concern still present? The system is operating correctly at thistime. The concern may have been causedby a loose or corroded connector. TESTDRIVE the vehicle above 32 km/h (20mph) and CARRY OUT at least one ABSstop.

Pinpoint Test J: Vehicle Pulls During Wheel speed sensor DTCs will automatically clearBraking or ABS False Activation/too when a successful test drive is carried out. ASensitive/Activates On a Normal Stop successful test drive should include speeds above 32

km/h (20 mph) and at least one ABS stop.Normal OperationThe wheel speed sensors are ‘‘active’’ sensors andgenerate a square wave signal that is sent to theABS module. When the ignition is turned to theRUN position, the ABS module carries out aself-test to determine if the sensors are functional.Voltage and ground are supplied to the front wheelspeed sensors from the ABS module along a pair ofwires.


• DTC C1222 Wheel Speed Mismatch When the vehicle speed exceeds 20 km/h (12 mph), if theABS module detects a difference between wheel speedsensor signals, DTC C1222 will be set. DTC C1222 canalso be set by damaged tone rings, mismatched wheeland/or tire sizes or driving the vehicle on one or moredeflated tires

• DTC C1233 LF Wheel Speed Sensor Signal Fault When the vehicle speed exceeds 20 km/h (12 mph), if the• DTC C1234 RF Wheel Speed Sensor Signal Fault ABS module does not receive a signal from the wheel• DTC C1235 RR Wheel Speed Sensor Signal Fault speed sensor, the appropriate DTC will be set. These• DTC C1236 LR Wheel Speed Sensor Signal Fault DTCs can also be set by an excessive wheel speed

sensor-to-tone ring air gap or a damaged tone ring

This pinpoint test is intended to diagnosethe following:

• Mismatched tire sizes

• Wheel speed sensor ring

• Wheel speed sensor

• ABS module

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST J: VEHICLE PULLS DURING BRAKING OR ABS FALSE ACTIVATION/TOO

SENSITIVE/ACTIVATES ON A NORMAL STOP


Test Step Result / Action to TakeJ1 CHECK THE ABS HARNESS AND MODULE FOR WATER

INTRUSION• Ignition OFF. Yes• Disconnect: ABS Module C155. CLEAN the connector and dry it out with• Inspect the ABS module connector and module for water low pressure compressed air. INSPECT

intrusion. for evidence of water entry and repair as• Is there any evidence of water entry? necessary. CLEAR the DTCs. TEST

DRIVE the vehicle above 32 km/h (20mph) and CARRY OUT at least one ABSstop.NoGO to J2.

J2 RETRIEVE ABS MODULE DTCs• Connect the scan tool. Yes• Are DTCs C1145, C1155, C1165 or C1175 present? GO to Pinpoint Test I.

NoIf DTC C1222 is present, GO to J7. ForDTC C1233 or C1234, GO to J6. For DTCC1235 or C1236, if the active wheel speedsensor tool is available, GO to J3. If theactive wheel speed sensor tool is notavailable, GO to J6.

J3 CHECK THE ABS MODULE OUTPUT USING THE SPECIALTOOL• Ignition OFF.• Disconnect: Suspect Wheel Speed Sensor.• Connect the special tool to the wheel speed sensor connectors. Yes• Ignition ON. GO to J5.• Select the correct system polarity on the special tool and turn

the special tool power switch to the ON position. No• Is the module output LED illuminated? GO to J4.

J4 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPENNOTE: Both circuits must be checked for each DTC.• Ignition OFF.• Disconnect: ABS Module C155.• For DTC C1233 (LF), measure the resistance between:

— ABS module C155-13, circuit 522 (TN/BK), harness sideand LF wheel speed sensor C150-2, circuit 522 (TN/BK),harness side.

— ABS module C155-12, circuit 521 (TN/OG), harness sideand LF wheel speed sensor C150-1, circuit 521 (TN/OG),harness side.

• For DTC C1234 (RF), measure the resistance between:— ABS module C155-26, circuit 514 (YE/RD), harness side

and RF wheel speed sensor C160-1, circuit 514 (YE/RD),harness side.

— ABS module C155-27, circuit 516 (YE/BK), harness sideand RF wheel speed sensor C160-2, circuit 516 (YE/BK),harness side.

• For DTC C1235 (RR), measure the resistance between:— ABS module C155-44, circuit 524 (PK/BK), harness side

and RR wheel speed sensor C426-2, circuit 524 (PK/BK),harness side.

— ABS module C155-43, circuit 523 (RD/PK), harness sideand RR wheel speed sensor C426-1, circuit 523 (RD/PK),harness side.

(Continued)

2008 E-Series, 10/2007



SENSITIVE/ACTIVATES ON A NORMAL STOP (Continued)

Test Step Result / Action to TakeJ4 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN

(Continued)

• For DTC C1236 (LR), measure the resistance between: Yes— ABS module C155-42, circuit 519 (LG/BK), harness side GO to J8.and LR wheel speed sensor C440-1, circuit 519 (LG/BK),harness side. No

— ABS module C155-41, circuit 518 (LG/RD), harness side REPAIR the affected circuit(s). TESTand LR wheel speed sensor C440-2, circuit 518 (LG/RD), DRIVE the vehicle above 32 km/h (20harness side. mph) and CARRY OUT at least one ABS

• Are the resistances less than 5 ohms? stop.J5 CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE

SPECIAL TOOL• Raise the suspect wheel until it can spin freely. Refer to Section Yes

100-02. INSPECT the wheel speed sensor tone• While monitoring the special tool, slowly spin the suspect wheel. ring for damage and looseness. INSTALL• Do the sensor output LEDs illuminate and flash and is the new components as necessary. If the tone

current overload LED not illuminated? ring is OK, the concern may have beencaused by a loose or corroded connector.CLEAR the DTCs. REPEAT the self-test.NoIf the current level LED is not illuminatedand the sensor output LEDs do notilluminate or if the current level LED isilluminated red, INSTALL a new wheelspeed sensor. REFER to Wheel SpeedSensor — Front and/or Wheel SpeedSensor — Rear in this section. TESTDRIVE the vehicle above 32 km/h (20mph) and CARRY OUT at least one ABSstop.If the current level LED is not illuminatedand the sensor output LEDs illuminategreen but do not flash, INSPECT thewheel speed sensor tone ring andINSTALL new if necessary. For the fronttone ring, REFER to Wheel SpeedSensor Ring — Front in this section. Forthe rear tone ring, REFER to Brake DiscRemoval and Intsallation in Section206-04. If the tone ring is OK, INSTALL anew wheel speed sensor, REFER toWheel Speed Sensor — Front and/orWheel Speed Sensor — Rear in thissection. TEST DRIVE the vehicle above32 km/h (20 mph) and CARRY OUT atleast one ABS stop.

J6 CHECK THE WHEEL SPEED SENSOR OUTPUT• Disconnect: Suspect Wheel Speed Sensor.

(Continued)

2008 E-Series, 10/2007




Test Step Result / Action to TakeJ6 CHECK THE WHEEL SPEED SENSOR OUTPUT (Continued)

• For DTC C1233 (LF), connect a fused (5A) jumper wire betweenLH front wheel speed sensor C150-1, circuit 521 (TN/OG),harness side and LH front wheel speed sensor pin-2, componentside. Connect the automotive meter between LH front wheelspeed sensor C150-2, circuit 522 (TN/BK), harness side and LHfront wheel speed sensor pin-1, component side.

• For DTC C1234 (RF), connect a fused (5A) jumper wirebetween RH front wheel speed sensor C160-1, circuit 514(YE/RD), harness side and RH front wheel speed sensor pin-1,component side. Connect the automotive meter between RHfront wheel speed sensor C160-2, circuit 516 (YE/BK), harnessside and pin-2, component side.

• For DTC C1235 (RR), connect a fused (5A) jumper wirebetween RH rear wheel speed sensor C426-1, circuit 523(RD/PK), harness side and RH rear wheel speed sensor pin-2,component side. Connect the automotive meter between RHrear wheel speed sensor C426-2, circuit 524 (PK/BK), harnessside and RH rear wheel speed sensor pin-1, component side.

• For DTC C1236 (LR), connect a fused (5A) jumper wirebetween LH rear wheel speed sensor C440-1, circuit 519 Yes(LG/BK), harness side and LH rear wheel speed sensor pin-1, GO to J8.component side. Connect the automotive meter between LHrear wheel speed sensor C440-2, circuit 518 (LG/RD), harness Noside and pin-2, component side. INSTALL a new wheel speed sensor.

• Ignition ON. REFER to Wheel Speed Sensor — Front• Measure the current while slightly rotating the wheel, using and/or Wheel Speed Sensor — Rear in

incremental turns. this section. CLEAR the DTCs. CARRY• Does the automotive meter switch between the low state (5 OUT the self-test with the brake pedal not

to 8 mA) and the high state (12 to 16 mA)? applied.J7 CHECK FOR CORRECT TIRE SIZE AND AIR PRESSURE

• Make sure all tire sizes are correct for the vehicle and that all 4 Yestires match. GO to J8.

• Make sure all tire pressures are correct. No• Clear the DTCs, drive the vehicle and carry out the self-test. The system is operating correctly at this• Is DTC C1222 still present? time.

(Continued)

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Test Step Result / Action to TakeJ8 CHECK FOR CORRECT ABS MODULE OPERATION

• Disconnect: ABS Module C155. Yes• Check the connector for: INSPECT the wheel speed sensor tone

ring for damage and looseness. INSTALL— evidence of water entry into the connector. new components as necessary. If the tone— corrosion. ring is OK, INSTALL a new ABS module.— pushed-out pins. REFER to Anti-Lock Brake System (ABS)— spread terminals. Module in this section. Using the scan• Connect: ABS Module C155. tool, CARRY OUT the IVD Initialization• Make sure the connector is fully seated and locked, then sequence. CLEAR the DTCs. CARRYoperate the system and verify the concern is still present. OUT the self-test with the brake pedal not• Is the concern still present? applied.NoThe system is operating correctly at thistime. The concern may have been causedby a loose or corroded connector. CLEARthe DTCs. CARRY OUT the self-test withthe brake pedal not applied.

Pinpoint Test K: DTCs B1104, C1277 and The steering wheel rotation sensor receives fusedC1278 — Steering Wheel Angle Sensor Fault ignition voltage from central junction box (CJB)and DTC C1963 — Stability Control Inhibit fuse 2 (10A) along circuit 640 (RD/YE), ground forWarning the sensor is provided by the ABS module alongRefer to Wiring Diagrams Cell 42, Vehicle circuit 1571 (BK). Steering wheel rotation (inDynamic Systems for schematic and connector degrees) is sent from the sensor to the ABS moduleinformation. along circuit 1572 (DG) and circuit 1573 (YE).

Normal OperationThe steering wheel rotation sensor monitors thesteering wheel position when the toothed-wheel onthe steering shaft passes through the optical field ofthe sensor.


• DTC B1104 Steering Angle Sensor Signal Error If during normal operation or the on-demand self test theABS module detects two back-to-back sensor edgeswithin one millisecond or steering angle sensor voltage isin an invalid range for 1.2 seconds, DTC B1104 will beset.

• DTC C1277 Steering Wheel Angle 1 and 2 Circuit If during normal operation or the on-demand self test theFailure ABS module detects an open circuit, short to voltage or

short to ground along circuits VCS06 (GY/BN) or VCS07(VT/OG), DTC C1277 will be set. An internal failure ofthe steering wheel rotation sensor may also cause DTCC1277 to set.

• DTC C1278 Steering Wheel Angle 1 and 2 Circuit If during normal operation or the on-demand self test theFaulted ABS module does not receive the steering wheel rotation

sensor input or if the input received does not agree withthe input from other sensors, DTC C1278 will be set.

• DTC C1963 Stability Control Inhibit Warning If conditions exist during normal operation that preventsthe roll stability control system from operating, DTCC1963 will be set. This DTC is usually set due to thesteering wheel rotation sensor or the stability controlsensor cluster being damaged or installed incorrectly.This DTC will not clear until the vehicle has been drivenabove 48 km/h (30 mph) with input from the steeringwheel rotation sensor.

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• Steering wheel rotation sensor

• ABS module

PINPOINT TEST K: DTCs B1104, C1277 AND C1278 — STEERING WHEEL ANGLE SENSOR FAULT ANDDTC C1963 — STABILITY CONTROL INHIBIT WARNING


NOTICE: Over tightening of the steering wheel rotation sensor fasteners may deform ordamage the sensor housing, possibly resulting in faulty operation.

NOTE: Make sure that the steering wheel rotation sensor is mounted securely to the columnwith 2 fasteners. A loose sensor or missing fastener may result in incorrect sensor operation.Examine the sensor/disk interface to make sure that the disk rotates freely within the slot ofthe sensor. Examine the disk for physical damage or blocked holes near the disk perimeter.Make sure that the sensor connector is mated securely to the harness connector. Beforeproceeding with electrical testing, make sure that the vehicle battery is fully charged.

Test Step Result / Action to TakeK1 CHECK THE STEERING WHEEL ROTATION SENSOR

INSTALLATION• Verify that the steering wheel rotation sensor is mounted Yes

correctly and both fasteners are installed. GO to K2.• Verify that the sensor disc is in good condition and free of Noobstructions and foreign materials. CLEAN the disc and/or INSTALL a new• Are the sensor and disc installed correctly and in good sensor or fastener(s) as necessary.condition? REFER to Steering Wheel Rotation

Sensor in this section.If DTC C1277 and/or C1278 are present,CLEAR the DTCs. Using the scan tool,CARRY OUT the IVD Initializationsequence. CARRY OUT the self-test withthe brake pedal not applied.If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.

K2 CHECK THE ABS HARNESS AND MODULE FOR WATERINTRUSION• Ignition OFF. Yes• Disconnect: ABS Module C155. CLEAN the connector and dry it out with• Inspect the ABS module connector and module for water low-pressure compressed air. INSPECT

intrusion. for evidence of water entry and repair as• Is there any evidence of water entry or corrosion? necessary. CLEAR the DTCs. CARRY

OUT the self-test with the brake pedal notapplied.NoGO to K3.

K3 CALIBRATE THE ABS MODULE• Connect: ABS Module C155.• Connect the scan tool.• Ignition ON.

(Continued)

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DIAGNOSIS AND TESTING (Continued)PINPOINT TEST K: DTCs B1104, C1277 AND C1278 — STEERING WHEEL ANGLE SENSOR FAULT AND

DTC C1963 — STABILITY CONTROL INHIBIT WARNING (Continued)

Test Step Result / Action to TakeK3 CALIBRATE THE ABS MODULE (Continued)

• Enter the following diagnostic mode on the scan tool: Clear theABS Module DTCs. Yes

• Enter the following diagnostic mode on the scan tool: IVD If DTC C1277, C1278 or C1963 areInitialization Sequence. retrieved or the IVD Initialization sequence

• Carry out the IVD Initialization sequence following the scan tool indicates a fault, GO to K4.directions. If any other DTCs are retrieved, GO to the• Test drive the vehicle above 48 km/h (30 mph) with input from ABS Module DTC Chart.the steering wheel rotation sensor.

• Enter the following diagnostic mode on the scan tool: Self Test NoABS Module. The system is operating correctly at this

• Are any DTCs retrieved or does the calibration procedure time. The concern may have been causedindicate a fault? by a loose or corroded connector.

K4 MONITOR THE STEERING WHEEL ANGLE POSITION (SWAPOS) PID• Enter the following diagnostic mode on the scan tool: Yes

DataLogger ABS Module. CLEAR the DTCs. DRIVE the vehicle• Monitor the SWA POS PID while rotating the steering wheel above 48 km/h (30 mph) with input from

clockwise and counterclockwise very slowly. the steering wheel rotation sensor.• Do the PIDs move in intervals of 4.5 degrees? RETRIEVE the DTCs.

If DTC C1277 or C1278 is still present,GO to GO to K12.If DTC C1963 is still present, GO toPinpoint Test L.NoGO to K5.

K5 CHECK FOR VOLTAGE TO THE STEERING WHEEL ROTATIONSENSORNOTE: The steering wheel rotation sensor connector is locatedbehind the instrument panel LH knee bolster.• Ignition OFF.• Disconnect: Steering Wheel Rotation Sensor C226.• Ignition ON.• Measure the voltage between steering wheel rotation sensor

C226-1, circuit 640 (RD/YE), harness side and ground.

YesGO to K6.NoVERIFY CJB fuse 2 (10A) is OK. If OK,REPAIR circuit 640 (RD/YE). Using thescan tool, CARRY OUT the IVDInitialization sequence. CLEAR the DTCs.CARRY OUT the self-test with the brake

• Is the voltage greater than 10 volts? pedal not applied.K6 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITS

FOR AN OPEN• Ignition OFF.• Disconnect: ABS Module C155.

(Continued)

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Test Step Result / Action to TakeK6 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITS

FOR AN OPEN (Continued)

• Measure the resistance between:— ABS module C155-10, circuit 1573 (YE), harness side and

steering wheel rotation sensor C226-2, circuit 1573 (YE),harness side.

— ABS module C155-39, circuit 1572 (DG), harness side andsteering wheel rotation sensor C226-3, circuit 1572 (DG),harness side.

— ABS module C155-24, circuit 1571 (BK), harness side andsteering wheel rotation sensor C226-4, circuit 1571 (BK),harness side.

YesGO to K7.NoREPAIR the affected circuit(s). Using thescan tool, CARRY OUT the IVDInitialization sequence. CLEAR the DTCs.CARRY OUT the self-test with the brake

• Are the resistances less than 5 ohms? pedal not applied.K7 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITS

FOR A SHORT TO VOLTAGE• Ignition ON.• Measure the voltage between ground and:

— ABS module C155-10, circuit 1573 (YE), harness side.— ABS module C155-39, circuit 1572 (DG), harness side.— ABS module C155-24, circuit 1571 (BK), harness side.

YesREPAIR the affected circuit(s). Using thescan tool, CARRY OUT the IVDInitialization sequence. CLEAR the DTCs.CARRY OUT the self-test with the brakepedal not applied.No

• Is any voltage present? GO to K8.K8 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITS

FOR A SHORT TO GROUND• Ignition OFF.

(Continued)

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Test Step Result / Action to TakeK8 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITS

FOR A SHORT TO GROUND (Continued)

• Measure the resistance between ground and:— ABS module C155-10, circuit 1573 (YE), harness side.— ABS module C155-39, circuit 1572 (DG), harness side.— ABS module C155-24, circuit 1571 (BK), harness side.

YesGO to K9.NoREPAIR the affected circuit(s). Using thescan tool, CARRY OUT the IVDInitialization sequence. CLEAR the DTCs.CARRY OUT the self-test with the brake

• Are the resistances greater than 10,000 ohms? pedal not applied.K9 CHECK THE STEERING WHEEL ROTATION SENSOR SIGNAL 1

OUTPUT• Connect: ABS Module C155.• Connect: Steering Wheel Rotation Sensor C226.• Ignition ON.• With C226 connected, backprobe the connector to measure the

voltage between steering wheel rotation sensor C226-3, circuit1572 (DG), harness side and steering wheel rotation sensorC226-4, circuit 1571 (BK), harness side while rotating thesteering wheel slightly.

Yes• Is the voltage between 0.25 volt and 0.75 volt or between GO to K10.4.00 volts and 4.75 volts with the steering wheel stationaryand change to the other state when rotating the steering Nowheel slightly? GO to K11.

(Continued)

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Test Step Result / Action to TakeK10 CHECK THE STEERING WHEEL ROTATION SENSOR SIGNAL 2

OUTPUT• With C226 connected, backprobe the connector to measure the

voltage between the steering wheel rotation sensor C226-2,circuit 1573 (YE), harness side and the steering wheel rotationsensor C226-4, circuit 1571 (BK), harness side while rotatingthe steering wheel slightly.

YesCLEAR the DTCs. DRIVE the vehicle.RETRIEVE the DTCs.If DTC C1277 or C1278 is retrieved again,GO to K11.If DTC C1963 is retrieved again, GO to• Is the voltage between 0.25 volt and 0.75 volt or between Pinpoint Test L.4.00 volts and 4.75 volts with the steering wheel stationary

and change to the other state when rotating the steering Nowheel slightly? GO to K11.

K11 CHECK FOR STEERING WHEEL ROTATION SENSORREFERENCE VOLTAGE• Ignition OFF.• Disconnect: Steering Wheel Rotation Sensor C226.• Ignition ON.• Measure the voltage between steering wheel rotation sensor

C2226-4, circuit 1571 (BK), harness side and:— steering wheel rotation sensor C226-3, circuit 1572 (DG),

harness side.— steering wheel rotation sensor C226-2, circuit 1573 (YE),

harness side.

YesIf sent here because DTC C1963 ispresent, GO to Pinpoint Test L.For all other DTCs and symptoms,INSTALL a new steering wheel rotationsensor. REFER to Steering WheelRotation Sensor in this section. Using thescan tool, CARRY OUT the IVDInitialization sequence. CLEAR the DTCs.CARRY OUT the self-test with the brakepedal not applied.No

• Are the voltages between 4.75 volts and 5.25 volts? GO to K12.

(Continued)

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Test Step Result / Action to TakeK12 CHECK FOR CORRECT ABS MODULE OPERATION

• Disconnect: ABS Module C155. Yes• Check the connector for: INSTALL a new ABS module. REFER to

Anti-Lock Brake System (ABS) Module in— corrosion. this section. CLEAR the DTCs. Using the— pushed-out pins. scan tool, CARRY OUT the IVD— spread terminals. Initialization sequence. CARRY OUT the• Connect: ABS Module C155. self-test with the brake pedal not applied.• Make sure the connector is fully seated and locked, thenoperate the system and verify the concern is still present. No

• Is the concern still present? The system is operating correctly at thistime. The concern may have been causedby a loose or corroded connector. CLEARthe DTCs. REPEAT the self-test.

Pinpoint Test L: DTCs C1279, C1280, C1281, Fused ignition voltage is sent to the stability controlC1282, C1516, C1517, C1963, C2769, C2770 sensor cluster from central junction box (CJB) fuseand U0028 — Sensor Cluster Fault and 2 (10A) along circuit 640 (RD/YE), ground for theVehicle Communication Bus Off sensor cluster is provided along circuit 57 (BK).Refer to Wiring Diagrams Cell 42, Vehicle The sensor cluster information is sent to the ABSDynamic Systems for schematic and connector module along the CAN2 bus circuits 1815 (PK/LB)information. and 1814 (WH/LB).

Normal OperationThe yaw rate sensor, roll rate sensor, lateralaccelerometer and longitudinal accelerometer are allpart of the stability control sensor cluster. Thestability control sensor cluster monitors themovement of the vehicle in relation to the directionof travel. As the vehicle moves, the information issent to the ABS module along the controller areanetwork secondary (CAN2) bus. The ABS modulecompares this information with other sensor inputsto determine if the vehicle is traveling in adirection other than what the driver is intending orif a roll stability event is taking place. If one orboth of the situations exist, the ABS module cantake the necessary action to bring the vehicle backto the intended course.


• DTC C1279 Yaw Rate Sensor Circuit Failure If during normal operation or the on-demand self test the• DTC C1281 Lateral Accelerometer Circuit Failure ABS module detects an open circuit, a short to voltage or• DTC C1517 Roll Rate Sensor Circuit Failure a short to ground on one or both of the CAN2 bus• DTC C2769 Longitudinal Acceleration Sensor Electrical circuits, the appropriate DTC will be set. Also, a failure

Failure of the sensor cluster will cause DTC C1279 to set.

• DTC C1280 Yaw Rate Sensor Signal Fault If during normal operation the ABS module does not• DTC C1282 Lateral Accelerometer Signal Fault receive the sensor cluster input or if the input received• DTC C1516 Roll Rate Sensor Signal Fault does not agree with the input from other sensors, the• DTC C2770 Longitudinal Acceleration Sensor appropriate DTC will be set.

Plausibility Failure

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• DTC C1963 Stability Control Inhibit Warning If conditions exist during normal operation that preventsthe roll stability control system from operating, DTCC1963 will be set. This DTC is usually set due to thesteering wheel rotation sensor or the stability controlsensor cluster being damaged or installed incorrectly.This DTC will not clear until the vehicle has been drivenabove 48 km/h (30 mph) with input from the steeringwheel rotation sensor.

• DTC U0028 Vehicle Communication Bus Off If during normal operation or the on-demand self test theABS module does not receive a message from the sensorcluster for 5 seconds or more, DTC U0028 will be set.



• Sensor cluster mounting

• Sensor cluster

PINPOINT TEST L: DTCs C1279, C1280, C1281, C1282, C1516, C1517, C1963, C2769, C2770 AND U0028— SENSOR CLUSTER FAULT AND VEHICLE COMMUNICATION BUS OFF


NOTE: The vehicle must be on level ground, at a complete standstill and not on a hoist whilecarrying out the initialization sequence or the pinpoint test steps. Any vehicle movement willresult in false PID value.

Test Step Result / Action to TakeL1 CHECK THE SENSOR CLUSTER MOUNTING AND MOUNTING

SURFACE• Ignition OFF. Yes• Inspect the sensor cluster mounting and make sure that the GO to L2.

bolts are fully seated and tightened correctly. Inspect the Nomounting surface for damage, corrosion or dirt. CLEAN and TIGHTEN the bolts to correct• Are the bolts fully tightened and are the cluster and specification. REPAIR the mountingmounting surfaces free of damage, dirt and/or corrosion? surface as necessary.If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.REPEAT the self-test.

L2 CALIBRATE THE ABS MODULE• Connect the scan tool.• Ignition ON.• Enter the following diagnostic mode on the scan tool: Clear the

ABS Module DTCs. Yes• Enter the following diagnostic mode on the scan tool: IVD GO to L3.Initialization Sequence.• Carry out the IVD Initialization sequence using the scan tool. No• Retrieve the ABS module DTCs. The system is operating correctly. The• Are any DTCs retrieved or does the IVD Initialization condition may have been caused by an

sequence indicate a fault? incomplete or inaccurate calibration.L3 CHECK THE VOLTAGE TO THE SENSOR CLUSTER

• Ignition OFF.• Disconnect: Stability Control Sensor Cluster C3073.• Ignition ON.

(Continued)

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DIAGNOSIS AND TESTING (Continued)PINPOINT TEST L: DTCs C1279, C1280, C1281, C1282, C1516, C1517, C1963, C2769, C2770 AND U0028

— SENSOR CLUSTER FAULT AND VEHICLE COMMUNICATION BUS OFF (Continued)

Test Step Result / Action to TakeL3 CHECK THE VOLTAGE TO THE SENSOR CLUSTER (Continued)

• NOTE: Operate the components/systems that share ignitionvoltage with the sensor cluster. Refer to Wiring Diagrams Cell13, Power Distribution for schematic and connector information.Measure the voltage between sensor cluster C3073-2, circuit640 (RD/YE), harness side and ground.

YesGO to L4.NoVERIFY CJB fuse 2 (10A) is OK. If OK,REPAIR circuit 640 (RD/YE).If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.

• Is the voltage greater than 10 volts? REPEAT the self-test.L4 CHECK CIRCUIT 57 (BK) FOR AN OPEN

• Ignition OFF.• NOTE: Operate the components/systems that share chassis

ground with the sensor cluster. Refer to Wiring Diagrams Cell10, Grounds for schematic and connector information.Measure the resistance between sensor cluster C3073-5, circuit57 (BK), harness side and ground.

YesGO to L5.NoREPAIR circuit 57 (BK).If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.

• Is the resistance less than 5 ohms? REPEAT the self-test.L5 CHECK THE CAN2 CIRCUITS FOR AN OPEN

• Disconnect: ABS Module C155.

(Continued)

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Test Step Result / Action to TakeL5 CHECK THE CAN2 CIRCUITS FOR AN OPEN (Continued)

• Measure the resistance between:— ABS module C155-20, circuit 1814 (WH/LB), harness side

and stability control sensor cluster C3073-3, circuit 1814(WH/LB), harness side.

— ABS module C155-34, circuit 1815 (PK/LB), harness sideand stability control sensor cluster C3073-4, circuit 1815(PK/LB), harness side.

YesGO to L6.NoREPAIR the affected circuit(s).If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.

• Are the resistances less than 5 ohms? REPEAT the self-test.L6 CHECK THE CAN2 CIRCUITS FOR A SHORT TO GROUND

• Ignition OFF.• Measure the resistance between ground and:

— stability control sensor cluster C3073-3, circuit 1814(WH/LB), harness side.

— stability control sensor cluster C3073-4, circuit 1815(PK/LB), harness side.

YesGO to L7.NoREPAIR the affected circuit(s).If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.

• Are the resistances greater than 10,000 ohms? REPEAT the self-test.

(Continued)

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Test Step Result / Action to TakeL7 CHECK THE CAN2 CIRCUITS FOR A SHORT TOGETHER

• Measure the resistance between stability control sensor clusterC3073-3, circuit 1814 (WH/LB), harness side and stability controlsensor cluster C3073-4, circuit 18145 (PK/LB), harness side

YesGO to L8.NoREPAIR the affected circuit(s).If DTC C1963 is present. CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms. CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.

• Is the resistance greater than 10,000 ohms? REPEAT the self-test.L8 CHECK THE CAN2 CIRCUITS FOR A SHORT TO VOLTAGE

• Ignition ON. Yes• Measure the voltage between ground and: REPAIR the affected circuit(s).

— stability control sensor cluster C3073-3, circuit 1814 If DTC C1963 is present, CLEAR the(WH/LB), harness side. DTCs. Using the scan tool, CARRY OUT

— stability control sensor cluster C3073-4, circuit 1815 the IVD Initialization sequence. DRIVE the(PK/LB), harness side. vehicle above 48 km/h (30 mph) with input

from the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRYOUT the IVD Initialization sequence.REPEAT the self-test.NoINSTALL a new stability control sensorcluster. REFER to Stability Control SensorCluster in this section.If DTC C1963 is present, CLEAR theDTCs. Using the scan tool, CARRY OUTthe IVD Initialization sequence. DRIVE thevehicle above 48 km/h (30 mph) with inputfrom the steering wheel rotation sensor.For all other DTCs and symptoms, CLEARthe DTCs. Using the scan tool, CARRY• Is any voltage present? OUT the IVD Initialization sequence.REPEAT the self-test.

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Pinpoint Test M: DTC C1288 — PressureTransducer Main/Primary Input CircuitFailure

Normal OperationThe ABS module monitors the brake pressuretransducer in combination with other brake inputs:wheel speed sensors, stoplamp switch from thePCM over the High Speed Controller AreaNetwork (HS-CAN) bus and lateral accelerometerfrom the sensor cluster. The pressure transducersignal is used by the ABS module for variousdiagnostic routines as well as to determine systemfunctionality. The pressure transducer is locatedinside the Hydraulic Control Unit (HCU) and can bemonitored via the master cylinder pressure(MC PRESS) PID. The PID should correlateclosely with system hydraulic pressure. When thevehicle is at rest without input from the brake pedal,this PID value should be at or close to 0 kPa (0psi). However, due to factors such as vehicle age orminor discrepancies in manufacturing, PID readingsmay have some variability. If the transducer requiresservice, a new HCU must be installed.

• DTC C1288 (Pressure Transducer Main/PrimaryInput Circuit Failure) — If during the ABSmodule self-test or normal operation a condition(such as a short or open circuit) occurs thatcauses the transducer signal to read above 1,710kPa (248 psi) when other inputs indicate anon-pressurized system, DTC C1288 will be set.

PINPOINT TEST M: DTC C1288 — PRESSURE TRANSDUCER MAIN/PRIMARY INPUT CIRCUIT FAILURE


Test Step Result / Action to TakeM1 MONITOR THE PCM BRAKE PEDAL POSITION (BPP/BOO) PID

• Connect the scan tool. Yes• Ignition ON. GO to M2.• Enter the following diagnostic mode on the scan tool: NoDataLogger PCM. RETRIEVE any PCM DTCs. REFER to the• Press and release the brake pedal while monitoring the Powertrain Control/Emissions DiagnosisBPP/BOO PID. (PC/ED) manual for non-communication• Does the PID switch to ON with the brake pedal pressed DTCs and REFER to Section 418-00 forand then to OFF with the brake pedal released? any communication DTCs.

M2 MONITOR THE ABS MODULE MASTER CYLINDER PRESSURE(MC PRES) PIDNOTE: To obtain the most accurate reading, it is recommended touse a graph display for this PID.NOTE: The initial pressure reading may be greater than 0. This is anormal condition. If the pedal is not pressed slowly, an initial spikemay occur.• Enter the following diagnostic mode on the scan tool:

DataLogger ABS Module.• Monitoring the MC PRESS PID, make a note of the initial

master cylinder pressure.

(Continued)

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DIAGNOSIS AND TESTING (Continued)PINPOINT TEST M: DTC C1288 — PRESSURE TRANSDUCER MAIN/PRIMARY INPUT CIRCUIT FAILURE

(Continued)

Test Step Result / Action to TakeM2 MONITOR THE ABS MODULE MASTER CYLINDER PRESSURE

(MC PRES) PID (Continued)

• Steadily press and release the brake pedal while monitoring theMC PRES PID. Yes• Does the PID smoothly increase with firm pressure on the GO to M3.brake pedal and then smoothly decrease with the brakepedal released, without any spikes, and does the final Nopressure match the recorded pressure within 0.5 psi? GO to M4.

M3 ROAD TEST THE VEHICLE AND MONITOR THE ABS MODULEMASTER CYLINDER PRESSURE (MC PRES) PID WHILEDRIVING THE VEHICLENOTE: To obtain the most accurate reading, it is recommended touse a graph display for this PID.NOTE: The initial pressure reading may be greater than 0. This is anormal condition. If the pedal is not pressed slowly, an initial spikemay occur.• Enter the following diagnostic mode on the scan tool:

DataLogger ABS Module.• Monitoring the MC PRESS PID, make a note of the initial Yesmaster cylinder pressure. The system is operating correctly at this• Road test the vehicle and have an assistant monitor the time. The concern may have been causedMC PRES PID. by a loose or corroded connector. CLEAR• Does the PID smoothly increase with firm pressure on the the DTCs. REPEAT the self-test.brake pedal and then smoothly decrease with the brake

pedal released, without any spikes, and does the final Nopressure match the recorded pressure within 0.5 psi? GO to M4.

M4 ISOLATE THE HCU• Install a new HCU. Refer to Hydraulic Control Unit (HCU) in this

section. Calibrate the ABS module. Follow the scan tooldirections for the calibration procedure.

• Enter the following diagnostic mode on the scan tool:DataLogger ABS Module.

• Monitoring the MC PRESS PID, make a note of the initialmaster cylinder pressure.

• NOTE: To obtain the most accurate reading, it is recommendedto use a graph display for this PID. Yes

The concern has been corrected.NOTE: The initial pressure reading may be greater than 0. ThisRETURN the vehicle to the customer.is a normal condition. If the pedal is not pressed slowly, an

initial spike may occur. NoSteadily press and release the brake pedal while monitoring the INSTALL a new ABS module, REFER toMC PRES PID. Anti-Lock Brake System (ABS) Module in

• Does the PID smoothly increase with firm pressure on the this section. Using the scan tool, CARRYbrake pedal and then smoothly decrease with the brake OUT the IVD Initialization sequence.pedal released, without any spikes, and does the final CLEAR the DTCs. REPEAT the self-testpressure match the recorded pressure within 0.5 psi? with the brake pedal not applied.

Pinpoint Test N: DTC C1446 — Base BrakeFailure/Brake Switch Stuck or Inoperative

Refer to Wiring Diagrams Cell 42, VehicleDynamic Systems for schematic and connectorinformation.

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This pinpoint test is intended to diagnoseNormal Operationthe following:The brake fluid level switch is hardwired to the

instrument cluster, a low fluid condition in the • Low brake fluidbrake fluid reservoir will cause the red brake

• Wiring, terminals or connectorswarning indicator to illuminate. The brake pedal

• Brake fluid level switchposition (BPP) switch is hardwired to the PCM. TheABS module receives brake pedal switch status • BPP switchfrom the PCM and brake fluid level status from the • ABS moduleinstrument cluster over the high-speed controllerarea network (HS-CAN) bus.

• DTC C1446 Base Brake Failure/Brake SwitchStuck or Inoperative — If during normaloperation the ABS module determines that theBPP switch information is invalid when comparedto other inputs or if the brake pedal message ismissing completely, DTC C1446 will be set.Also, a low brake fluid level in the mastercylinder reservoir or an open, short to ground orshort to voltage in the brake fluid level switchthat the SJB interprets as a low fluid conditionwill cause DTC C1446 to be set.

PINPOINT TEST N: DTC C1446 — BASE BRAKE FAILURE/BRAKE SWITCH STUCK OR INOPERATIVE

Test Step Result / Action to TakeN1 CHECK FOR ABS MODULE COMMUNICATION (U-CODE) DTCs

• Connect the scan tool.• Ignition ON.• Enter the following diagnostic mode on the scan tool: Self Test YesABS Module. REFER to Section 418-00 to diagnose the• Carry out the ABS module self-test. Retrieve and record any HS-CAN bus.ABS module DTCs.• Are DTCs U0073, U0115 and/or U0155 retrieved with DTC No

C1446? GO to N2.N2 CHECK THE BRAKE FLUID LEVEL

• Check the brake fluid level in the master cylinder reservoir. Yes• Is the brake fluid at an acceptable level? GO to N3.

NoFILL the master cylinder reservoir to anacceptable level. CLEAR the DTCs.REPEAT the self-test.If DTC C1446 returns, GO to N3.If DTC C1446 does not return, REFER toDiagnosis and Testing in Section 206-00to diagnose the base brake system.

N3 VERIFY RED BRAKE WARNING INDICATOR OPERATION• Ignition OFF. Yes• Monitor the red brake warning indicator. GO to N4.• Ignition ON. No• Does the red brake warning indicator illuminate for a short REFER to Diagnosis and Testing inperiod and then go out? Section 413-01 to diagnose the red brake

warning indicator and brake fluid levelsensor.

N4 MONITOR THE PCM BRAKE PEDAL POSITION (BPP/BOO) PID• Enter the following diagnostic mode on the scan tool: YesDataLogger PCM. GO to N6.• Firmly press and release the brake pedal while monitoring the

BPP/BOO PID. No• Does the PID agree with the brake pedal position? GO to N5.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST N: DTC C1446 — BASE BRAKE FAILURE/BRAKE SWITCH STUCK OR INOPERATIVE

(Continued)

Test Step Result / Action to TakeN5 VERIFY CORRECT STOPLAMP OPERATION

• Press and release the brake pedal. Yes• Have an assistant monitor the stoplamps. GO to N5.• Do the stoplamps operate correctly? No

REFER to Stoplamps in Section 417-01 tocontinue diagnosis of the BPP switch.

N6 MONITOR THE ABS MODULE BRAKE ON/OFF (BOO ABS) PID• Enter the following diagnostic mode on the scan tool: Yes

DataLogger ABS Module. The system is operating correctly at this• Firmly press and release the brake pedal while monitoring the time. The concern may have been caused

ABS module BOO ABS PID. by a loose or corroded connector. CLEAR• Did the PID agree with the brake pedal position? the DTCs. CARRY OUT the self-test with

the brake pedal not applied.NoREFER to Section 418-00 to diagnose theHS-CAN bus.

This pinpoint test is intended to diagnosePinpoint Test O: DTC C1991 — Modulethe following:Calibration Failure

• ABS moduleNormal OperationThe ABS module needs to be calibrated whenever a • Sensor clustercomponent specific to the roll stability control • Steering wheel rotation sensor(RSC) system or electronic stability control (ESC)system is disconnected or a new component isinstalled. Calibration allows the ABS module toidentify the ‘‘zero position’’ of the sensors so thesystem will operate correctly.

PINPOINT TEST O: DTC C1991 — MODULE CALIBRATION FAILURE

NOTE: The stability assist active/fail lamp flashes when a system calibration is required.Calibration is required after certain DTCs are cleared.

NOTE: The vehicle must be on level ground, at a complete standstill and not on a hoist whilecarrying out the calibration procedure. Any vehicle movement will result in calibration failure.

Test Step Result / Action to TakeO1 CHECK FOR ABS MODULE DTCs

• Connect the scan tool. Yes• Ignition ON. DIAGNOSE all other DTCs first. GO to the• Retrieve the recorded DTCs. ABS Module DTC Chart.• Is any other DTC retrieved with C1991? Some of the pinpoint tests recommend

ABS module calibration prior to any furtherdiagnostics. In this case, GO to O2.NoGO to O2.

O2 CALIBRATE THE ABS MODULE• Enter the following diagnostic mode on the scan tool: IVD (ESC) YesInitialization Sequence. GO to O3.• NOTE: Be sure to rotate the steering wheel lock-to-lock during

Nothe calibration of the ABS module.GO to O4.Carry out the IVD (ESC) initialization sequence per the scan tool

instructions. Some concerns cause the calibration not• Does the IVD (ESC) initialization sequence complete for all to complete. If sent here from another

of the stability assist sensors and does the stability assist pinpoint test, return to that pinpoint test foractive/fail lamp stop flashing and turn off? further diagnostics.

(Continued)

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DIAGNOSIS AND TESTING (Continued)PINPOINT TEST O: DTC C1991 — MODULE CALIBRATION FAILURE (Continued)

Test Step Result / Action to TakeO3 CLEAR DTC C1991

• Using the scan tool, clear the DTC. Yes• Does the DTC clear? TEST DRIVE the vehicle. REPEAT the

self-test.If sent here from another pinpoint test,return to that pinpoint test for furtherdiagnostics.NoGO to O4.

O4 MONITOR THE STEERING WHEEL ANGLE POSITION (SWAPOS) PID• Enter the following diagnostic mode on the scan tool: YesDataLogger ABS Module. GO to Pinpoint Test L.• Monitor the SWA POS PID while rotating the steering wheel

clockwise and counterclockwise very slowly. No• Do the PIDs move in intervals of 4.5 degrees? GO to Pinpoint Test K.

Pinpoint Test P: The Traction Control The traction control system can be disabled bySystem Cannot Be Disabled/Enabled or the pressing the traction control switch located on theTraction Control System is Inoperative instrument panel. When the system is disabled, the

traction control OFF indicator on the switch willRefer to Wiring Diagrams Cell 42, Vehicleilluminate and the message center (if equipped)Dynamic Systems for schematic and connectorwill display Traction Control Off.information.

Fused battery voltage to disable the system and toNormal Operationilluminate the traction control OFF indicator isThe standard ABS module with engine only tractionsupplied to the traction control switch from centralcontrol (EOTC) sends wheel speed sensorjunction box (CJB) fuse 22 (15A) along circuit 729information to the PCM along the high-speed(RD/WH). When the traction control switch iscontroller area network (HS-CAN) bus. The PCMpressed, the voltage is supplied through the switchcompares the front wheel speed sensor informationto the instrument cluster along circuit 959 (GY).to the rear wheel speed sensor information toThe instrument cluster then grounds circuit 960determine if traction control is necessary. If traction(BK/LB) which illuminates the traction control OFFcontrol is necessary, the PCM limits engine torqueindicator in the switch.by regulating fuel and spark to the cylinders, to

control the wheel slip. At the same time, the PCM • DTC C1093 Traction Control Disable Switchsends the instrument cluster a message over the Circuit Failure — If during normal operation theHS-CAN bus to flash the traction control indicator. instrument cluster detects voltage on circuit 959The traction control indicator informs the driver that (GY) for more than 2 minutes or if the instrumenta traction control event is taking place. cluster detects voltage on 959 (GY) at all during

the on-demand self test, DTC C1093 will be set.The ABS module with traction control and rollstability control (RSC) sends monitors the wheel This pinpoint test is intended to diagnosespeed sensor information to determine if traction the following:control is necessary. If traction control is necessary,

• Fusethe ABS module sends a request to the PCM along• PCM configurationthe HS-CAN bus which limits engine torque by

regulating fuel and spark to the cylinders. At the • Instrument cluster configurationsame time, the ABS module sends the instrument

• Wiring, terminals or connectorscluster a message over the HS-CAN bus to flash the

• Traction control switchtraction control indicator. The traction controlindicator informs the driver that a traction control • HS-CAN busevent is taking place. • PCM

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST P: THE TRACTION CONTROL SYSTEM CANNOT BE DISABLED/ENABLED OR THE

TRACTION CONTROL SYSTEM IS INOPERATIVE


Test Step Result / Action to TakeP1 RECONFIGURE THE PCM

• Connect the scan tool. Yes• Ignition ON. GO to P2.• Enter the following diagnostic mode on the scan tool: Module NoReconfiguration PCM. The system is operating correctly at this• Reconfigure the PCM. time. The concern may have been caused• Test drive the vehicle and verify that the concern is still present. by a incorrectly configured instrument• Is the concern still present? cluster.

P2 RECONFIGURE THE INSTRUMENT CLUSTER• Connect the scan tool. Yes• Ignition ON. GO to P3.• Enter the following diagnostic mode on the scan tool: Module NoReconfiguration Instrument Cluster. The system is operating correctly at this• Reconfigure the instrument cluster. time. The concern may have been caused• Test drive the vehicle and verify that the concern is still present. by a incorrectly configured instrument• Is the concern still present? cluster.

P3 CHECK FOR DTCs• Check for any ABS module, instrument cluster, PCM or Yes

communication DTCs. For ABS module DTCs, REFER to the• Are any DTCs present? ABS Module DTC Chart.

For instrument cluster DTCs, REFER tothe Instrument Cluster DTC Chart.For PCM DTCs, PowertrainControl/Emissions Diagnosis (PC/ED)manual.For communication DTCs, REFER to theMaster DTC Chart in Section 419-10.NoGO to P4.

P4 CHECK FOR VOLTAGE AT THE TRACTION CONTROL SWITCHNOTE: The traction control switch connector is located behind theinstrument cluster finish panel.• Ignition OFF.• Disconnect: Traction Control Switch C280.• Ignition ON.• Measure the voltage between ground and:

— traction control switch C280-5, circuit 729 (RD/WH), harnessside.

— traction control switch C280-6, circuit 729 (RD/WH), harnessside.

YesGO to P5.NoVERIFY CJB fuse 22 (15A) is OK. If OK,REPAIR circuit 729 (RD/WH). CLEAR the

• Is the voltage greater than 10 volts? DTC. REPEAT the self-test.

(Continued)

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TRACTION CONTROL SYSTEM IS INOPERATIVE (Continued)

Test Step Result / Action to TakeP5 CHECK THE TRACTION CONTROL SWITCH

• Measure the resistance between traction control switch C280 Yespin-1, component side, and traction control switch C280 pin-6, GO to P6.component side while pressing and releasing the switch. No• Is the resistance greater than 10,000 ohms with the switch INSTALL a new traction control switch.released and less than 5 ohms with the switch pressed? CLEAR the DTC. REPEAT the self-test.

P6 CHECK CIRCUIT 959 (GY) FOR A SHORT TO VOLTAGE• Ignition OFF.• Disconnect: Instrument Cluster C220a.• Ignition ON.• Measure the voltage between traction control switch C280-1,

circuit 959 (GY), harness side and ground.

YesREPAIR circuit 959 (GY). CLEAR theDTC. REPEAT the self-test.No

• Is the voltage greater than 10 volts? GO to P7.P7 CHECK CIRCUIT 959 (GY) FOR A SHORT TO GROUND

• Ignition OFF.• Measure the resistance between traction control switch C280-1,


YesGO to P8.NoREPAIR circuit 959 (GY). CLEAR the

• Is the resistance greater than 10,000 ohms? DTC. REPEAT the self-test.

(Continued)

2008 E-Series, 10/2007



TRACTION CONTROL SYSTEM IS INOPERATIVE (Continued)

Test Step Result / Action to TakeP8 CHECK CIRCUIT 959 (GY) FOR AN OPEN

• Measure the resistance between instrument cluster C220a-15,circuit 959 (GY), harness side and traction control switchC280-1, circuit 959 (GY), harness side.

YesGO to P9.NoREPAIR circuit 959 (GY). CLEAR the

• Is the resistance less than 5 ohms? DTC. REPEAT the self-test.P9 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION

• Ignition OFF.• Check instrument cluster C220a for: Yes

INSTALL a new instrument cluster.— corrosion. REFER to Section 413-01. CLEAR the— pushed-out pins. DTC. REPEAT the self-test.— spread terminal.• Connect: Instrument Cluster C220a. No• Make sure the connector is seated correctly then operate the The system is operating correctly at this

system and verify the concern is still present. time. Concern may have been caused by• Is the concern still present? a loose or corroded connector.

Pinpoint Test Q: The Traction Control OFF Fused battery voltage to disable the system and toIndicator (in the Switch) is Always/Never On illuminate the traction control OFF indicator is

supplied to the traction control switch from centralRefer to Wiring Diagrams Cell 42, Vehiclejunction box (CJB) fuse 22 (15A) along circuit 729Dynamic Systems for schematic and connector(RD/WH). When the traction control switch isinformation.pressed, the voltage is supplied through the switch

Normal Operation to the instrument cluster along circuit 959 (GY).The traction control system can be disabled by The instrument cluster then grounds circuit 960pressing the traction control switch located on the (BK/LB) which illuminates the traction control OFFinstrument panel. When the system is disabled, the indicator in the switch.traction control OFF indicator in the switch will

• DTC C1105 Traction Control Disable Lampilluminate and the message center (if equipped)Circuit Short to Battery — If the instrumentwill display Traction Control Off.cluster detects a short to voltage along circuit 960(BK/LB) during normal operation or theon-demand self test, DTC C1105 will be set.



• Traction control switch

• Instrument cluster

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST Q: THE TRACTION CONTROL OFF INDICATOR (IN THE SWITCH) IS ALWAYS/NEVER

ON


Test Step Result / Action to TakeQ1 CHECK THE TRACTION CONTROL SWITCH

NOTE: The traction control switch connector is located behind theinstrument cluster finish panel.• Ignition OFF.• Disconnect: Traction Control Switch C280. Yes• Measure the resistance between traction control switch C280 GO to Q2.pin-1, component side, and traction control switch C280 pin-6,

component side while pressing and releasing the switch. No• Is the resistance greater than 10,000 ohms with the switch INSTALL a new traction control switch.

released and less than 5 ohms with the switch pressed? CLEAR the DTC. REPEAT the self-test.Q2 CHECK CIRCUIT 959 (GY) FOR A SHORT TO VOLTAGE

• Disconnect: Instrument Cluster C220a.• Ignition ON.• Measure the voltage between traction control switch C280-1,


YesREPAIR circuit 959 (GY). CLEAR theDTC. REPEAT the self-test.No

• Is any voltage present? GO to Q3.Q3 CHECK CIRCUIT 960 (BK/LB) FOR A SHORT TO VOLTAGE

• Measure the voltage between traction control switch C280-4,circuit 960 (BK/LB), harness side and ground.

YesREPAIR circuit 960 (BK/LB). CLEAR theDTC. REPEAT the self-test.No

• Is any voltage present? GO to Q4.Q4 CHECK CIRCUIT 960 (BK/LB) FOR A SHORT TO GROUND

• Ignition OFF.

(Continued)

2008 E-Series, 10/2007



ON (Continued)

Test Step Result / Action to TakeQ4 CHECK CIRCUIT 960 (BK/LB) FOR A SHORT TO GROUND

(Continued)

• Measure the resistance between traction control switch C280-4,circuit 960 (BK/LB), harness side and ground.

YesGO to Q5.NoREPAIR circuit 960 (BK/LB). CLEAR the

• Is the resistance greater than 10,000 ohms? DTC. REPEAT the self-test.Q5 CHECK THE INSTRUMENT CLUSTER FOR A SHORT TO

GROUND• Connect: Instrument Cluster C220a.• Measure the resistance between traction control switch C280-4,

circuit 960 (BK/LB), harness side and ground.

YesGO to Q6.No

• Is the resistance greater than 10,000 ohms? GO to Q7.Q6 CHECK THE INSTRUMENT CLUSTER FOR A SHORT TO

VOLTAGE• Ignition ON.

(Continued)

2008 E-Series, 10/2007



ON (Continued)

Test Step Result / Action to TakeQ6 CHECK THE INSTRUMENT CLUSTER FOR A SHORT TO

VOLTAGE (Continued)

• Measure the voltage between traction control switch C280-4,circuit 960 (BK/LB), harness side and ground.

YesGO to Q7.NoThe system is operating correctly at thistime. Concern may have been caused bya loose or corroded connector. CLEAR the

• Is any voltage present? DTC. REPEAT the self-test.Q7 CHECK FOR CORRECT PCM OPERATION

• Ignition OFF.• Disconnect: Instrument Cluster C220a.• Check the connector for: Yes

INSTALL a new instrument cluster.— corrosion. REFER to Section 413-01. CLEAR the— pushed-out pins. DTC. REPEAT the self-test.— spread terminal.• Connect: Instrument Cluster C220a. No• Make sure the connector is seated correctly then operate the The system is operating correctly at this

system and verify the concern is still present. time. Concern may have been caused by• Is the concern still present? a loose or corroded connector.

This pinpoint test is intended to diagnosePinpoint Test R: DTC B2900 — VINthe following:Mismatched

• Module configurationNormal OperationWhen the ignition is turned to the RUN position, • ABS modulethe ABS module and the PCM exchange vehicleidentification number (VIN) information over thehigh speed controller area network (HS-CAN) bus.If the VIN information stored in the ABS moduledoes not match the information transmitted by thePCM, DTC B2900 will set.

PINPOINT TEST R: DTC B2900 — VIN MISMATCHED

Test Step Result / Action to TakeR1 VERIFY PCM VIN

• Connect the scan tool. Yes• Ignition ON. GO to R2.• Using the scan tool, carry out the Network Test. No• Enter the following diagnostic mode on the scan tool: Log RECONFIGURE the PCM. FOLLOW theViewer. instructions on the scan tool. CLEAR the• Compare the VIN in Log Viewer to the vehicle VIN plate. DTCs. CYCLE the ignition key. REPEAT• Does VIN in Log Viewer match the vehicle VIN plate? the self test.

(Continued)

2008 E-Series, 10/2007


DIAGNOSIS AND TESTING (Continued)PINPOINT TEST R: DTC B2900 — VIN MISMATCHED (Continued)

Test Step Result / Action to TakeR2 VERIFY ABS MODULE PART NUMBER

• Retrieve and record the ABS module part number from Log YesViewer and verify that the vehicle has the correct ABS module CONFIGURE the ABS module. REFER toinstalled. Section 418-01, Programmable Module

• Is the correct ABS module installed in the vehicle? Installation (PMI) Using the IntegratedDiagnostic System (IDS) When theOriginal Module is NOT Available. CLEARthe DTC. CYCLE the ignition key.REPEAT the self test.NoINSTALL a new ABS module. REFER toAnti-Lock Brake System (ABS) Module inthis section. CLEAR the DTC. CYCLE theignition key. REPEAT the self test.

2008 E-Series, 10/2007

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