Differential

U0100-LOST COMMUNICATION WITH ECM/PCM (FDCM)

For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


- 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 ECM/PCM 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 all 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 ECM/PCM IS ACTIVE ON THE BUS

Turn the ignition on.

With the scan tool, select Network Diagnostics.

Verify that the PCM is active on the bus.

Is the PCM active on the bus?

Yes

- Go To 4

No

- Refer to the No Response test procedure.


4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS

With the scan tool, select Network Diagnostics.

Is there more than one module with active DTCs "Logged Against" the PCM?

Yes

- Replace the PCM.
- Perform the appropriate VERIFICATION TEST. Verification Tests

No

- Replace the module that set this DTC.
- Perform the appropriate VERIFICATION TEST. Verification Tests