letco enterprises presents€¦ · – (mfjb) mega fuse junction block – (mgjb) main ground...

LETCO Enterprises Presents:

Freightliner P‐3 Cascadia Overview and HVAC System Design

Cascadia P‐3 2007‐2018

Cascadia Electronic Architecture

Cascadia Network Topology

1

New Green Diagnostic Connector

4

• The new connector is backwards compatible with vehicles built prior to model year 2016 that have a black pin receptacle.

• If the first generation USB-Link device is used a new adapter cable with the green 9-pin connector must be used, and the software driver must be version 9.3.1.0 or higher.

Entertainment

Exterior Brake

Driver Information

Vehicle Network Architecture Cascadia 2016 Telematics & 3rd parties

DriverAssistanceCabin Powertrain Hybrid

PT 3rd parties

Body & Trailer

Backbone

DIAGNOSTICS‐CAN

CABIN‐CAN J1939‐CAN

J1939 open

PT‐CAN

J1939‐CAN

SSL

SWB

switches

IPPC

CumminsECM

3rd PartyTCM

PLC4TrucksSAE J2497 ESP

XTrailerABS

7TrailerABS

TPMS

SRS

LDWS

VRDU2

Assistance‐CA

NSAM CAB

CPC4SSR

CGWCGW

SAS

ABS

ICU3/4MeGauges

UDSJ1939

MCM

ACM

TCM

VRDU

MPC

RDF

MQ‐Bus

ACC‐D

ACC-R

ECAS

HVACPCU

HVACACU

HVACFCU

SAM CHAS

MSF

FMS

J1939Radio

Tablet3rd Party Telematics

CTP ‐ FBPlus VT

Cabin CAN CGW03T

Department 6

500K CGW03

Department 7

250K CGW03

Department 8

Power Distribution 07‐early 10The Cascadia has two common 

electrical blocks:MFJB (MEGA Fuse 

Junction Block)

• Houses up to 5 fuses

• Provides cleaner power & higher voltage to cab and engine control systems than the old method of attaching them to starter stud.

• ECU’ s supplied dedicated power / grounds

MGJB (Main GroundJunction Block)

• A junction for connecting grounds to the battery.

Starter

Alternator

Load Cut-off Switch

MGJB

MFJB

SAM cabin

SAM chassis

Power Train PDM

Battery

+

+

+

+

+

+

+

+

-

-

-

-

-

-

-

+ -

+ -

Trailer PDM (opt)

Inverter (opt)

2

Power Distribution Components Emergency Power Feed 

Cascadia Specific• Emergency power for 

SAM Cab comes from the starter positive stud to the PTPDM fuse F7 

• SAM Cab uses power from F7 for LVD function also

• Alternator sense • 2010 Fuse B in PNDB.• 2010 Fuse D Alt Sense.  

Starter

Alternator

Load Cut-off Switch

MGJB

MFJB

SAM cabin

SAM chassis

Power Train PDM

Battery

+

+

+

+

+

+

+

+

-

-

-

-

-

-

-

+ -

+ -

Trailer PDM (opt)

Inverter (opt)

SAM cab EmergencyPower Feed/LVD sense F6

F7

IGNrelay

ALT sense

2

Power Distribution Mid 2010‐15

– Power Distribution Modules (PDM) contained in SAM’s

– Additional  PowerTrain PDM 2007 and Up. 

– Emergency power feed from starter stud to fuses F‐6 and F‐7 of PowerTrain PDM to feed SAM’s if Mega Fuse fails or open cut‐off switch.

– Auxiliary PDMs depending on options.

– (MFJB) MEGA Fuse Junction Block– (MGJB) Main Ground Junction 

Block – Load Cut‐off Switch

Emergency Power Symptoms

Note:The lights that are activated during emergency power failure may not be the same for all trucks because of hard ware, soft ware, and programmable parameters.

If the Mega fuse that feeds power to the SAM Cab fails:

2

Load Disconnect Switch 07‐09

Load Disconnect Switch Update07‐09 MFJB andLoad Disconnect Switch

Power Net Distribution BoxCab Load Disconnect Switch

PNDB LED’s

Cab Load Disconnect Switch Power Net Distribution Box

PNDB TroubleshootingWhen the Cab Load Disconnect Switch (CLDS) is in the on position, an LED on the switch and another on the PNDB will be illuminated. If there is an error with the PNDB, the LED will flash at a ½ second rate. The PNDB will make a double flash if it was not able to switch on or off when commanded by the CLDS.If any of the fuses are open, conventional troubleshooting methods need to be used. The LED’s in the PNDB and switch are not affected by open fuses or load circuits.

LED on Cab Load Disconnect Switch (CLDS) is Flashing

Step Test Procedure Test Result Action

1Does the LED make a double flash for 5 seconds when the

switch is first turned on or off?

YesThe PNDB failed to switch itself on or off

when commanded by the switch. Replace a defective PNDB

No

Inspect the connectors in the interconnect harness between the PNDB and the cab load disconnect switch (CLDS). If either was not correctly seated or there is corrosion in the

connections, clean and reconnect. Otherwise, continue with step 2.

2

Measure continuity on the harness between the PNDB

and the CLDS. Are any of the circuits open or shorted to

ground?

Yes Repair the wiring fault as appropriate.

NoSubstitute a good CLDS to check if this

repair the problem. Otherwise replace the PNDB.

2

The Cascadia has Two SAM’s

SAM Cabin SAM Chassis

Cascadia is a Module Driven Truck Using SAM’s: (Signal detection & Activation Modules)

SAM’s are similar to the Main PDM used on the Century/Columbia they contain:

• Circuit protection and relays

• The SAM Cab and SAM Chassis control the basic electrical devices on the truck, like the BHM and CHM on an M2

• Both contain ECU’s that control vehicle electrical system

• ECU’s are connected by a data link

• Utilizes Inputs from Switches or Data

• Many Outputs are FET controlled

SAM Cabin

SAM Chassis

SAM Cab  Module

• Signal Detection and Actuation Module

• SAM Cab Located under the Glove Box (similar to P‐2 Main PDM location)

• Houses fuses, relays and FETs• SAM Cab controls most cab 

functions• Communicates with other modules 

via CAN

SAM Chassis Module

• SAM Chassis Located under the hood on the front bulkhead on the drivers side of cab.

• Houses  fuses, relays and FET’s

• SAM Chassis controls most chassis functions

• Communicates with other modules via CAN

• Is part of the Multiplexed electrical system

SAM Tips:Water or Corrosion in the Sam Cabin will 

causes:

• Starter to engage when the unit is running down the road.

• The Engine Fan will come on without request.

• The A/C Clutch will engage without Request.

Water in the SAM Chassis or loose Ground:

• Bunk Lighting and Switches go Crazy

• Right rear Tail Lamp on all the time

• No Trailer Lights or Fuses for turn lights keep blowing.

SAM CABIN

SAM Chassis

Sam Chassis and PT PDM Issues: Missing Covers!

MSF (Modular Switch Field) 

MSF Master (ECU) ‐ connected to the CAN Datalink through Starpoint connectorMSF Sub panels ‐ uses a proprietary sub‐bus DatalinkHard wire input to MSF Master: Stalk switch, Rotary switch Steering wheel switches

1

MSF Tips

• If Cruise Control Drops Out, Reflash• Dome Lights Stay On Unplug Connector D for two Minutes.• Headlamps on all the time, Check Connector E for proper 

seating.• Four‐Way Flasher Flashes 2X Reboot Module.

E

D

Central Gateway Module (CGW) 

• Located under Doghouse• Acts as a translator and router 

between the Cabin CAN J1939 and J1708

• Is the Interface between Service Link and Cabin CAN ECU’s

• Available as a SGW (Simplified Gateway Module) 2010 forward.

SAE J1708(9.6kbs)

A B

C

D E

F

G H

J

SAE J1939-139-pin connector

Diagnostics CAN(500kbps)

Central Gateway

Cabin CAN(125kbps)

SAE J1939

CGW Tips

No CAN present:J1939 & J1708 present,Truck not in Emergency Power,Check Diagnostic Connector Pins H and J for 60 Ohms ResistanceCheck Pins 18 and 23 on CGWCheck Fuse F20 in SAM Cab  (2 AMP)

Terminal Retention Issues At Central Gateway 2016

• Wire used for the data wiring is from supplier Champlin Cable, for both the 18 and 20 AWG.

• The insulation used on the wire is EXRAD 150 FX, 20 mill wall thickness with Outer Diameter between (1.88mm –2.08)

• The connector used at the Central Gateway is a 23-13151-011 Micro Quadlock.

• The connector was designed to be used with TXL style wire. The TXL has a max OD on the insulation of 1.90mm, which mates good with the connector.

• When DTNA changed over to OBD16 in January, it was discovered that the new wire has insulation that is at the max opening of the connector.

• The 500k wire for H1939 is running around 1.98 mm. which is slightly larger that of the TXL.

New Gateway Module A66-01045-002

No Programing required

New Gateway Modules have “1” resistor built inside for the

H1939 & J1939 Data links. Only one EOL resistor is

needed.

Terminal Retention Issues At Central Gateway 2016

• The larger insulation diameter is making it difficult for PKC to get the terminal's to seat and lock into the connector.

• Trucks have made it through the plants process and validation testing without seeing any issues or failures.

• Once trucks are in operation it is possible to have a terminal that isn’t locked into the connector shake loose and have a weak connection or….now you have it, but now you don’t connection. (or no connection at all)

• This is leading to communication errors and depending on vehicle configuration cause no start or a intermittent start issue.

• The SAM cabin wouldn’t get the message that its ok to start from the transmission because the Gateway isn’t properly connected.

Starpoint Connector

– Located under the dash on the dog house

– Connects the CAN ECU’s to the CAN Datalink

– Has a 60 Ohm resistor across data bus legs

Starpoint Tip:

If the Starpoint Connection Malfunctions, all the Panel lights and the Front HVAC Controller will be flashing!

• Check each Legs for 60 Ohms Resistance.

CPC (Common Powertrain Controller) Detroit and MB Power only

2010 Electronic Control Modules

1) Aftertreatment Control Module (ACM) 

2) Motor Control Module 2 (MCM2)            

3) Common Powertrain Controller 2+ 

1 2

3

ACM MCM2

CPC2+

1

Power Train Control ModulesPower Train Control Modules

EPA10 GHG14

CPC2+ CPC4

MCM2T MCM 2.1

ACM2T ACM 2.1

NA TCM01T

Close but not the Same!

StarPoint: Black Connector SharePoint: Yellow Connector

DT‐12  12 Speed Automated 

Towing Precautions

•The ACM communicates with the MCM2 and CPC2+ via a dedicated CAN line

•Like DDEC VI modules it transmits data messages via the Unified Diagnostics Services protocol.  

•Electronic diagnostics is  done using the DDDL / DDRS / Drumroll family of tools/Diagnostic Link

•Programming the ACM follows procedures similar to MCM programming

Detroit Communications

P‐2 Wiring Harness

Multiplexed Electrical System

o Electrical devices, lamps, gauges, switch outputs – controlled by an ECU

o Use data links to send multiple signals to ECUs at tremendous speeds

o System can both– Perform tasks– Monitor components

o The communication by Datalinks:decreases total number of wires required. 

o By connecting switches to ECUs. The ECUs can then share switch information on the Datalink with other ECUs.

Multiplexing Topology

A B

C

D E

F

G H

J

LOW AIRPRESSURE

SWITCH

AMBIENTTEMP

SENSOR

J15897/J1708JUNCTION BLOCK

TERMINATINGRESISTOR 1

TERMINATINGRESISTOR 2

Black = Hardwire

Green = J1939

Purple = Sub Bus

Orange = J1587

Blue = Cabin CAN

Brown Diag CAN

Red = DDC

How to Kill a Data Line! 

Data Links – J1587/J1708

Data Links ‐ J1587/J1708• Low speed – 9600 bps• Twisted pair of wires• Orange/Dark Green• Connected to all ECUs that 

require this link (some through CGW)

• ECUs share data• Engine transmits a good bit 

of data• Typically runs dash gauges

J1939 Data Link• High speed – 250K bps• Twisted pair of wires• Dark Green/Yellow• Backbone architecture• Terminating resistors• Cab 33 Code !

Datalink J1939 4

ENGINECONTROLMODULE

PNEUMATIC

MODULEABS

TRANSMISSIONCONTROLMODULE

INSTRUMENTCLUSTER

HVAC CONTROL SWITCHES ·FRONT

HVAC CONTROL SWITCHES ·REAR

J193

9(2

50kb

ps)

A B

C

D E

F

G H

J

SAE J1939-139-pin connector

TerminatingResistor #1

TerminatingResistor #2

CAN (Controller Area Network)► High speed – 125K bps► Twisted pair of wires► Light Blue/White► Proprietary data link 

connecting SAM Cab SAM Chassis MFS Master CGW

► Above ECUs are connected at Starpoint connector that has 60 ohms of resistance 

► Can share information on both J1587/J1708 and J1939

► Connect to the CGW so the Cabin CAN ECUs can interface with ServiceLink

Datalink Cabin CAN

Starpo

int

Data Links Diagnostic CAN

Diagnostic CAN:• 512k bps • Twisted pair of wires • Brown with a blue stripe and 

brown with a white strip • Connects to CGW  and goes 

to the Diagnostic connector • Note that this is a higher 

speed than the cabin CAN• Point to Point Topology

Cascadia Clutch Request

29 HVAC DTC’s available through J1939 Data Link

Cascadia A/C System Components

• Sanden Compressor 2007‐09• Denso Compressor 2010‐current• Block TXV• Receiver/Drier • Condenser/Evaporator• Evaporator Temperature Sensor• Constant Output Temperature Sensor• Refrigerant Pressure Transducer• Low Air Pressure Switch• Ambient Air Temperature Sensor 2007 ‐09.

Sanden SHD Compressor 07‐09

• Shipped with 10 Ounces SP‐20 PAG Oil.

• Thermal fuse built into Field Coil for Belt Protection

Denso Compressor 2010 Forward

Shipped with 4.4 Ounces of ND‐8 PAG OilMini Stat‐O‐Seals: 14‐16 Ft Lbs.Red Label: DD enginesBlue Label: Cummins ISX

Thermal Sensor in Series with Clutch Power  for Belt Protection.

Cascadia Component Details

Block TXV TXV and Evaporator

3 oz. Oil

Cascadia Component Details

Condenser Use Temperature Testing to Find Problems

1 oz. OilNormal Temperature Drop 20-50 Degrees F

Cascadia Component Details

Receiver DrierLines and Fittings

Torque to 14-16 Ft Lbs.

3 oz. Oil1 oz. Oil per line

Refrigerant Oil for Replacement Components Summary

Refrigerant Charge 

Typical Charge:Cab Cab: 3.00 lbs.Sleeper: 4.12 lbs.Refer to Label on Unit or use ServicePro for exact amount.Confirm with Temperature Drop Test.

Cascadia HVAC Module Details

Valeo ‐ blend airDirect drive actuators (No external drive gears)Barrel doors instead of Flapper designSame blower motor used for the Front box and Bunk

Cascadia Temperature and Air Delivery Controls

• Control Head• 4 Electric Stepper Motors• 4 Doors: Defrost, Floor, Blend, and Recirculation• 2 Temperature Sensors: Evaporator and Duct • Recirculation Filter• Fresh Air Filter (outside of Front wall)• Brushless Blower Motor

Front Control Unit (FCU) 

Front Control Unit (FCU) – ECU for front HVAC systemFCU communicates with other ECUs on J1939.FCU controls the four stepper motors.FCU determines when the A/C compressor should operate and sends request to SAM CABFCU can remotely control the bunk HVAC unit (bunk over‐ride).

Day Cab

SLEEPER CAB

Recirculation Mode

20 minute time out Must push to return to Recirculation

Front Control Panel Layout

Stepper MotorsSame Motor All Locations

Must Calibrate If Disconnected or Replaced

Actuator Motor DTC

Stepper Motor Recalibration

• Ignition On/ Engine Off• Blower mode to Off (CCW)• Temperature mode  to Full Heat (CW)• Mode selector to Face (CCW)• Press A/C and Recirc together until LED’s begin to flash.• Recalibration complete when the LED’s stop flashing.

Temperature Sensors

COTC

Evaporator

Sensor Detail

COTC Sensor Evaporator Sensor

One Step Two Steps

Sensor Bench Test

Evaporator @ 32 F:8910‐9090 Ohms  

COTC @ 32 F:31254‐34046 Ohms

Cabin Filters

Recirculation Filter Cabin Filter

Brushless Blower Motor Permanent Magnets (6)

Brushless Motor ‐ Coils

Cage

Same Motor in M2

Cascadia Compressor Clutch  Operation

Air Pressure 

Reads Off Primary Air TankN.O. Switch in Series with Secondary Tank SwitchChopped signal from SAM Cab Connector-Pin X13-10 to X13-11.

Ambient Temperature Sensor

Bumper Mounted Sensor Driver Side Mirror 2014 Up

Ambient Temperature DTC

ACP

Air Conditioning Pressure Transducer:Schrader Mounted.05 volts to 4.8 Volts normal operating range.Open circuit = No clutch and Full time engine fan.

Pressure Transducer DTC

HVAC ServiceLink Template

No Clutch Engagement Tips:

ACP Connection backed outConnecter C‐22, Pin 1 broken wire at terminalClutch Ground wire on mag switch connection at starter

Auxiliary Control Unit (ACU)

• ACU communicates over the J1939 with other ECUs.

• The auxiliary control unit (ACU) – ECU for bunk HVAC system.

• ACU controls the stepper motor in the bunk HVAC to operate a temperature mix door.

• ACU controls the bunk unit blower motor.

• ACU can remotely control the front HVAC when the parking brake is set.

J1939 Data Line Missing

Condensation from duct dripping into Sub Control Panel

HVAC Auxiliary Unit

Rear Control Panel Layout

Cascadia ParkSmart Auxiliary HVAC System Introduction

275 AMP Alternator

Battery Separator Switch

4 Additional Batteries

Pre-2011 Box

Heater

ParkSmart• The temperature control knob has 21 

positions, each of which correspond to a desired cabin temperature between 60 and 85 degrees F.

• A sensor in the climate control panel monitors the cabin temperature.

• Dependent upon cabin temp and desired temp, the controller will either turn on  the auxiliary A/C system or the fuel‐operated coolant heater.

• The fan speed is manually selected; 0 is off, and 8 is maximum.

• The blower must be on a position other than “off” for the system to operate.

Unit Location

Relay/Fuse Panel

(Relocated to side of unit mid-summer 2011)

Actuator

Heater Core Access

1

ParkSmart System Operation

• Important Note: The system is designed to maintain a desired cabin temperature for a given period of time which depends heavily on ambient outside temperature and solar load.

• The unit does not have the capacity to raise or lower the cabin temperature significantly.• The vehicle should be brought to desired temperature with the engine driven HVAC system prior to 

shutting down and entering parked mode.To operate the ParkSmart unit in engine running mode simply select the desired temperature and blower 

speed.For parked‐mode operation, set the desired temperature and a blower speed other than zero then push the 

Park button. The LED on the Park button will then illuminate and the unit will start running. 

External Components

Internal Components

ParkSmart Revision ‐ Rev5

Revision 5 July 2011 

The condenser was relocated from under the cab to the back of the sleeper in order to improve airflow to the condenser and get it away from the radiant heat of the pavement.

This change required hoses and connections for manufacturing and has a single service port on the high side line.

R134a Charge: 2.00 LBS. POE Oil Required!

ParkSmart Revision ‐ Rev5

Electronics Moved in to Storage Bin

ParkSmart Revision ‐ Rev5

ESPAR heater fuel pump and filter relocated to fuel tank

Auxiliary PNDB with Optimized Idle System, No Battery Separator

Cascadia

Some Additional Tips

Wiring Diagram Notes 2

Wiring Diagram Types:A = AssemblyD = InstallationG = SubsystemL = Layout06 = Electrical12 = Air System

24 Volts vs AGM Batteries!

GHG2014 Change

DiagnosticLink is here

RUN SMART!

Thank You for Your Attention!

Larry can be reached at:LTURAY1974@aol.com

P2 Century/Columbia Class

• HVAC Controls

Century Class Inputs, Outputs, and Control 

Inputs

Duct Sensor

Blower MotorVariable voltagesignal

Bunkover ride

_ +Outputs

Aux HVAC Data LinkControl

EvaporatorSensor Thermistor

Blower Speed Mode Temp

RECRIC A/C

A/C Clutch

Binary Switch

Door Actuators

ModeRecirc/Fresh

Temp

Century Class Cab Blend Air Unit

Mode Actuator

Temperature Actuator

Heater Core Cover

Evaporator Core Cover

Recirc. Actuator

Recirc. Air Inlet (Filter not shown)

Century Class Cab Blend Air(front wall view)

Expansion Valve

Outside Air Inlet

Evaporator Tubes

Drain Tube

Heater hoseConnections

Floor Outlet

Defrost Outlet

SWD Outlet

Face Louver Outlet

Cabin Filter P‐2

Century Class Clutch Control

ECU monitored controls temp 37 – 44 degreesA/C clutch on @ 44 degree or higher

to get FCU to request A/C clutch on.

Evaporator Sensor

Century Class CDTC Sensor

ECU monitored to controltemperature by moving blend 

air door

Constant Discharge Temperature Control Sensor

P‐2 Switches

P‐2 Blower Motor

Century Blower Motor runs, No A/C Clutch

P‐2 Template

P2 Recalibration

• Key On,  Engine Off• Blower: Off• Mode: Defrost• Temp: Full Heat• Press: Recir and A/C together, hold until LED’s start to Blink• Blower runs on high speed, mode doors will cycle, Recir door opens and closes• Process complete when LED’s turn off.

Refrigerant and Oil Specs

No A/C Clutch

TSB

M‐2

DD‐5

DD‐5

DD‐5

M‐2

M‐2

M‐2

M‐2

M‐2