U0252

U0252-LOST COMMUNICATION WITH TRAILER LIGHTING MODULE





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition on.

Battery voltage between 10 and 16 volts.

IOD fuse installed.

FCM is configured correctly.

- Set Condition:
Bus messages not received from the Trailer Lighting Module (TM) for approximately 2 to 5 seconds.





Diagnostic Test

1. VERIFY DTC IS ACTIVE
NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

With the scan tool, read active DTCs.
Is this DTC active?

Yes

- Go To 2

No

- Refer to the Stored Lost Communication test procedure. Stored Lost Communication DTCs

2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS
With the scan tool, read active DTCs from all modules.

NOTE: Check for FCM configuration, CAN B or C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.

Does the scan tool display any active DTCs to the conditions listed above?

Yes

- Diagnose and repair the DTC.

No

- Go To 3

3. VERIFY THAT THE TIRM IS ACTIVE ON THE BUS
Turn the ignition on.
With the scan tool, select Network View and select Advanced.

NOTE: A red X will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.

Verify that the TIRM is active on the bus.
Is the TIRM active on the bus?

Yes

- Replace and program the Front Control Module.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.

No

- Go To 4

4. (A114) FUSED B(+) CIRCUIT OPEN




Turn the ignition off.
Disconnect the Traffic Information Receiver Module harness connector.
Using a 12-volt test light connected to ground, check the (A114) Fused B(+) circuit.
Does the test light illuminate brightly?

Yes

- Go To 5

No

- Repair the (A114) Fused B(+) circuit for an open or short.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.

5. (Z909) GROUND CIRCUIT OPEN




Using a 12-volt test light connected to 12-volts, check the (Z909) ground circuit.
Does the test light illuminate brightly?

Yes

- Go To 6

No

- Repair the (Z909) ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.

6. (D55) AND (D54) CAN B BUS CIRCUITS OPEN




NOTE: One open circuit will not cause this condition.

Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.
Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.
Is there any voltage present on either circuit?

Yes

- Replace the Trailer Lighting Module.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.

No

- Repair the (D55) and (D54) CAN B Bus circuits for an open. Inspect the connector for damage.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.