ford eec iv operation and testing. overview ect map/baro tps ckp/cmp o2s egr position act ks boo ac...
TRANSCRIPT
Ford EEC IV
Operation and Testing
Overview
ECTMAP/BAROTPSCKP/CMPO2SEGR PositionACTKSBOOACPower Steering
PCM
A/F MixtureIgnition Timing
Idle SpeedThermactor Airflow
Canister PurgeEGR Flow
TCCAC Fan
WOT Cut OffInlet Air Temp
Fuel Pump RelayTurbo Boost
Operating Modes
Base Engine Strategy
MPG Lean Cruise
Modulator Strategy
Limited Operational Strategy
Adaptive Strategy
Base Engine Strategy
Used to control warm engine runningOpen Loop starts at 130o
Warm up mode sub modesCrankingClosed-throttlePart throttle (closed loop)Wide-open throttle (WOT)
PCM controls actuators for good driveability
MPG Lean Cruise
Some engines beginning 1988
Certain criteria are met
Goes out of closed-loop fuel control
Very lean for economy at cruise
Modulator Strategy
Conditions that require significant change from Base Engine StrategyCold engineOverheated engineHigh altitude
Limited Operational Strategy
Component Failure
Protect other componentsConverter
Substitute values from another sensorMAP TPSECT IATEGR Disable EGR
Adaptive Strategy
Started in 1985PCM has base mapMonitors operation and modifies base mapCompensates for wear etc.Dirty Injectors
Are in response to O2SStored in KAM
Adaptive Strategy
Adaptive Strategy
Adaptive Strategy
Adaptive Strategy
Inputs
ECTMAP/BAROTPSCKP/CMPO2SEGR PositionACTKSBOOACPower Steering
PCM
A/F MixtureIgnition Timing
Idle SpeedThermactor Airflow
Canister PurgeEGR Flow
TCCAC Fan
WOT Cut OffInlet Air Temp
Fuel Pump RelayTurbo Boost
Engine Coolant TempThermistorVoltage to PCM is 4.5 cold to .3 hotResistance 470K cold to 1k hotInfluences PCM’s calibrations for A/F Raito Idle Speed Thermactor Air Canister Purge Choke Voltage, Temp compensated accel pump Upshift light
Pressure Sensors
MAP, BARO
Pressure-sensitive capacitor
Convert to frequency out100 Hz no load Idle159 Hz atmospheric (WOT)
Voltage will go from 0 to 5 at the frequency above
Pressure SensorsMAP used for BAROPCM uses Key On before cranking and
WOT for BARO calculations.
BARO used with Vane Airflow Sensors
Looks like MAP with collar
Throttle Position Sensor
Some adjustable, some notPotentiometer3 wires, 5v reference, ground, signalTwo common problemsBad spot, signal dropoutBad ground
Full reference on signalBiased high
Profile Ignition Pickup (PIP)
Hall Effect Switch
Engine speed and crank position
In distributor
One vane narrower for location
Profile Ignition Pickup (PIP)
On DIS sensor is on front of engine
One vane for each pair of companion cylinders
Most PIP signals go from .4v or less to battery voltage at 10o BTDC
Cylinder Identification (CID)Used with Distributorless Ignition
PIP doesn't know which stroke
Driven at cam speed
Also usedfor SFI
4 Cylinder PIP CIDOn DIS, 1 & 4 fire together
CID is on crank with PIP
Ignition Diagnostic Monitor
Used on TFI systems
Checks to see that spark occurred
Wire with 22k from Tach wire to PCM
Makes sure SPOUT command is carried out
Makes sure timing advance is working
Knock Sensor (KS)
Piezoelectric type
Vibration sends signal to PCM
PCM retards timing 1/2o per engine revolution
Intake Air Temp Sensor (IAT)
Was called Air Charge Temp (ACT) before OBDII
Thermistor
Voltages and resistance same as ECT
A/F and advance
Used on most Fords
EGR Position (EVP)Feedback (PFE)
EVP Linear Potentiometer only monitors position
EVP Black and White physically interchangeablePFE is like MAP but gives a voltage Measures exhaust pressure under EGR valve
PFE measures flow used to Fine tune EGR position Fine tune A/F ratio Modify ignition timing
Vane Air Flow (VAF)
Used with VAT and BP to calculate Speed Density
Mass Airflow MAF
Beginning in 1988
Uses sample tube
Uses hot wire
Encased in Glass
200o above ambient
A/F and Timing
Transmission Switches
PCM knows if in gear, park or neutral
Affects Idle air control strategyFor A/T because converter loads engine
Response to rapid throttle closing
Transmission Switches
AXOD uses 3 switchesNeutral Pressure NPSTrans Hydraulic THS 3-2Trans Hydraulic THS 4-3
AXOD Trans Temp TTS opens over 275oFWill apply TCC if temps get high like uphill
climb
Can tell which gear except if it is in 1 or 2
Transmission Switches
Transmission Switches
Manual TransNeutral Gear Switch NGSClutch Engaged Switch CESWired in parallel so both must be open for
PCM to know car is in gear.
Brake On/Off BOO
In stop lamp switch
A4LD has PCM controlled converter lockup
Used on most models today
Increases idle when in gear and brakes are on
May disengage AC on prolonged idle
Vehicle Speed Sensor (VSS)
Speedometer output Mechanical or electric
speedometer.
8 cycles per revolution128000 signals per mileUsed for TCC lockup Coolant fan control Identify deceleration
Other Inputs
Power Steering Pressure Switch PSPSOpens between 400 and 600 PSI Increases idle speed
AC Demand (ACD)
AC Clutch Cycling Switch (ACCS)PCM watches to increase idle speed
Outputs
ECTMAP/BAROTPSCKP/CMPO2SEGR PositionACTKSBOOACPower Steering
PCM
A/F MixtureIgnition Timing
Idle SpeedThermactor Airflow
Canister PurgeEGR Flow
TCCAC Fan
WOT Cut OffInlet Air Temp
Fuel Pump RelayTurbo Boost
Air / Fuel Mixture Control
Three typesFeedback CarburetorsCentral Fuel Injection (TBI)Electronic Fuel Injection (PFI)
Non SequentialGroupSequential
Feedback CarburetorsMotorcraft & Carter uses solenoid to bleed air into idle and main metering circuits
Holley Carburetors
Holley uses remote solenoid with similar idle control
Holley Carburetors
Uses vacuum diaphragm and valve for main metering control
Central Fuel Injection
Low Pressure SystemSingle injector
Low Pressure SystemTwo injectorsAlternates injectors
ECM grounds to turn on
Pulse Width Modulated
Central Fuel Injection
CFI Fuel Delivery
Port Fuel Injection (EFI)
Port Fuel Injection
Non-sequential (EFI)
Group or bank-to-bankTwo Groups
Sequential (SEFI) Injectors pulsed one at a time in firing orderUsed throughout product line by early
1990s
Injector Removal
Fuel Supply System
Fuel Supply System
Fuel Pump In tankTrucks may have a lift and pressure pumpMost are around 39 psiPressure relief at 100 psi
Fuel Supply System
Pressure regulatorManifold pressure modifiedLow of 30 around psi (deceleration)High of 39 psi (WOT)Turbocharged may go as high as 50 psiCFI does not use manifold pressure.
High pressure 38-40 psiLow pressure 14.5 psi
Fuel Supply SystemFuel Pump Relay PCM Controlled
Turns on with key for 1-2 seconds or until PIP signal is present.
Inertia Switch is in series with pump
Thick Film Integrated (TFI-IV)Thick film refers to the type of semi-conductorControls spark primarySends PIP to PCMPCM modifies and sends back SPOUTSPOUT tells TFI when to turn primary on and off.In distributor or “Closed Bowl”
Thick Film Integrated (TFI-IV)
Thick Film Integrated (TFI-IV)
Closed BowlTFI Module
Octane rod can change base timing while keeping rotor right.
Distributorless Ignition
PCM controls dwell and timing
DIS module is like TFI module
Also uses SPOUT Now called Spark Angle Word (SAW)
1991 second generation using Reluctance instead of Hall sensors
35 teeth on crank 36 minus1 for position
Distributorless Ignition
Base Timing CheckRemove SPOUT/SAW jumper10o Self check adds 20o
Octane adjustment jumper looks like SPOUT Retards 3o to 4o and can be left out
Spout Connectors
Idle Speed
Carbs & CFI use Throttle kickerDC motor idle speed control (ISC)
Idle Tracking Switch Senses closed throttle PCM then operates ISC
Act as Idle Dashpot
EFI Idle Speed Control
Air bypass solenoidPCM Controlled
Duty Cycle pintle valve
Also a dashpot
Thermactor Air Management
Thermactor Air Bypass (TAB)Thermactor Air Diverter (TAD)PCM Controlled
Thermactor Air Management
CTS Below 50o TAB groundedSends air to atmosphere
Between 50 and 190 Bypass valve sends air to diverter and to manifoldOver 190 closed loop and air goes to CatBypass at idle, WOT, and with failing O2S
Open Loop Tip
The fastest way to see if vehicle is in open loop is to see where the air is going
Cat = Closed Loop
Atmosphere or manifold = Closed Loop
Provided thermactor system is working
Canister PurgeThree types
Constant purge with no PCM control
PCM controlled in-line solenoid
PCM controlled with temperature controlled vacuum valve
Canister Purge/Heat Control
To valve that warms intake
manifold
EGR Control
EGR Control and EGR Vent
2 solenoids that are “dithered”
EGR Control
EGR Shutoff Solenoid Uses one solenoid Controls ported vacuum
EGR Shutoff Solenoid with Backpressure Transducer One solenoid Strength of vacuum controlled by transducer Does not have EVP sensor
EGR Control
Vacuum Regulator
Introduced in 1985 and is used for most applications
EEC IV Diagnosis
Codes follow self test
Codes can be read Manually
Watch MILHook up meter
Star IIOther scan tool
Notice the safety glasses
Slow and Fast Codes
Slow codes can be read with pulsing meter or MIL
Fast codes can be read by scan tool
Fast codes precede slow and look like a momentary flashing.
Diagnostic Connector
KOEO Self Test Procedures
Engine warm
Turn off for 10 seconds
KOEO, then ground STI
Test will run, then read codes
All accessories off
2.5L and 4.9L hold clutch fully in.
KOEO Self Test Codes
KOER Self Test Procedures
Engine warm 2000 RPM 2 min
Turn off for 10 seconds
KOER, then ground STI
Test will run, then read ID codes
Push brake and turn steering wheel
After code 10 (or 1 flash) snap WOT
KOER Self Test Codes
Computed Timing
Pull SPOUT/SAWCheck for 10o with timing light
Reinstall SPOUT/SAW
Run KOER self testAt end of last code, 20o will be added to
base timing for 2 min.
Other Tests
Continuous monitor (wiggle)After last code, deactivate and reactivate
self test Wiggle wires etc. Fault will display
SEFI Cylinder Balance
KOER after last code, tip throttle and release.