Pinpoint Test BH: PSCM (Power Steering Control Module) DTC (Diagnostic Trouble Code) U0137:00 Lost Communication With Trailer Brake Control Module

Refer to Power Steering Controls for schematic and connector information.

Normal Operation and Fault Conditions

The PSCM monitors the HS-CAN messages when the ignition has been on for more than 5 seconds, the voltage to the PSCM is greater than 10 volts and there are no Diagnostic Trouble Codes (DTCs) present inhibiting PSCM operation

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PSCM U0137:00	Lost Communication With Trailer Brake Control Module: No Sub Type Information	This DTC sets when the PSCM does not receive the TBM messages within a certain time frame. This can occur if the TBM wiring harness or electrical connectors are loose or damaged, or if the vehicle battery state of charge levels are low.

Possible Causes

Fuse(s)
Wiring, terminals or connectors
TBM

BH1 VERIFY PSCM (POWER STEERING CONTROL MODULE) DTC (DIAGNOSTIC TROUBLE CODE)

Ignition ON.

Clear the PSCMDTC s.

Ignition OFF.

Ignition ON.

Carry out the PSCM self-test.

Is DTC U0137:00 currently present and active in the PSCM '

Yes

GO to BH2

No	If the PSCM does NOT list DTC U0137 Lost Communication With The TBM, DISCONTINUE this test and REFER to the DTC Chart for diagnostic direction.

BH2 CHECK THE VEHICLE BATTERY AND CHARGING SYSTEM VOLTAGE
- Ignition ON.
- REFER to: Battery and carry out Pinpoint Test A: Battery Condition Test (battery state of charge).
Did the battery pass the condition test (battery state of charge)?

Yes GO to BH3

No INSTALL a new 12-volt battery. REFER to: Battery . GO to BH3

BH3 INSPECT THE PSCM (POWER STEERING CONTROL MODULE) COMMUNICATION WIRING AND CONNECTORS

Ignition OFF.

Inspect all disconnected connectors for:
- Pushed-out pins, loose pins, bent pins, spread terminals, water ingress and corrosion.
- Missing or loose latches, broken or cracked connector housings.
- VDB wiring for pinched or cut wiring under brackets, air cleaner boxes, battery trays, engine pulleys, etc.

Inspect the VDB wiring for pinched or cut wiring under brackets, air cleaner boxes, battery trays, engine pulleys, etc.

Inspect the VDB wiring harness anchors for coming loose from anchoring locations in the engine compartment.

Repair the connectors or wiring as necessary.

Ignition ON.

Clear the PSCMDTC s.

Ignition OFF.

Ignition ON.

Carry out the PSCM self-test.

Is DTC U0137:00 currently present and active in the PSCM '

Yes

GO to BH4

No	The concern is not present at this time and may have been set due to a loose or damaged electrical connector. The test is complete, no further action is required.

BH4 CHECK THE HS-CAN (HIGH-SPEED CONTROLLER AREA NETWORK) CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect GWM connector, C2431.

Disconnect PSCM _A connector, C1463B.

Measure the resistance between:

Positive Lead	Measurement / Action	Negative Lead
C1463B Pin 2	Courtesy of FORD MOTOR COMPANY	C2431 Pin 18
C1463B Pin 3	Courtesy of FORD MOTOR COMPANY	C2431 Pin 17

Are the resistances less than 3 ohms?

Yes	The HS-CAN circuits are OK, GO to BH5

No	REPAIR the circuit.

BH5 RECHECK FOR PSCM (POWER STEERING CONTROL MODULE) DTC (DIAGNOSTIC TROUBLE CODE) U0137:XX

Connect PSCM C1463B. Make sure the connector seats and latches correctly.

Connect GWM connector, C2431. Make sure the connector seats and latches correctly.

Ignition ON.

Clear the PSCMDTC s.

Ignition OFF.

Ignition ON.

Carry out the PSCM self-test.

Is DTC U0137:00 currently present and active in the PSCM '

Yes	The PSCMHS-CAN circuits are working correctly at this time. RETRIEVE and RECORD all TBMDTCs. REFER to: Auxiliary Brake System . DIAGNOSE the TBM.

No	If the PSCM no longer lists DTC U0137::xx, the concern was repaired during this pinpoint test and the PSCMHS-CAN circuits are working correctly at this time.