U0100

U0100-LOST COMMUNICATION WITH ECM/PCM







- When Monitored:
With the ignition on.

Battery voltage between 10 and 16 volts.

Ignition Off Draw (IOD) fuse installed.

Totally Integrated Power Module (TIPM) is configured correctly.

- Set Condition:
Bus messages not received from the Engine Control Module/Powertrain Control Module (ECM/PCM) for approximately one second.





1. VERIFY THE DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE

NOTE: Make sure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

NOTE: Check for any Technical Service Bulletins (TSBs) related to the condition. If a TSB applies, perform the procedure outlined in the TSB before continuing.

1. Using the scan tool, read active DTCs.

Is this DTC active?

Yes

- Go To 2

No

- Stored Lost Communication DTCs Perform the Stored Lost Communication DTCs diagnostic procedure.

2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS
1. Using 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

- Go to and perform the appropriate diagnostic procedure.

No

- Go To 3

3. VERIFY THAT THE ECM/PCM IS ACTIVE ON THE BUS
1. Turn the ignition on.
2. Using the scan tool, select ECU View.
3. Verify that the ECM/PCM is active on the bus.

Is the ECM/PCM active on the bus?

Yes

- Go To 4

No

- Manufacturer Code Charts Perform the No Response from ECM/PCM diagnostic procedure.

4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS
1. Using the scan tool, select Network View and select Advanced.

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

Yes

- Replace/update the Engine Control Module/Powertrain Control Module.
- Perform the ECM or PCM VERIFICATION TEST. PCM Verification Test for gasoline engine applications.

No

- Replace/update the module that set this DTC.
- Perform the appropriate verification test for the module being replaced. If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Body Verification Test.