Communications

U0100-LOST COMMUNICATION WITH ECM/PCM





For a complete wiring diagram Refer to Diagrams/Electrical.


- When Monitored:
With the ignition on.

Battery voltage between 10 and 16 volts.

IOD fuse installed.

TIPM 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. Manufacturer Code Charts .



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

NOTE: Check for TIPM 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 ECM/PCM is active on the bus.
Is the ECM/PCM active on the bus?

Yes


- Go To 4


No


- Refer to the No Response test procedureInitial Inspection and Diagnostic Overview . Manufacturer Code Charts .



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 ECM/PCM?

Yes


- Replace/update the ECM/PCM.
- Perform the appropriate VERIFICATION TESTVerification Tests .


No


- Replace/update the module that set this DTC.
- Perform the appropriate VERIFICATION TESTVerification Tests .