U0101-00

U0101-00-LOST COMMUNICATION WITH TCM

For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:

- Ignition on, battery voltage between 9 and 16 volts.
- Set Condition:
If the Anti-Lock Brakes System (ABS) Module fails to receive bus messages from the Transmission Control Module (TCM) for approximately 500 ms.





NOTE: If present, diagnose and repair DTC U0002-88-CAN C BUS OFF PERFORMANCE- BUS OFF before diagnosing this DTC.

1. VERIFY THE DTC IS ACTIVE

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

1. Ignition on, engine not running.
2. With the scan tool, read and record ABS DTCs.
3. With the scan tool, read and record Environmental Data (EV Data).
4. With the scan tool, erase ABS DTCs.
5. Cycle the ignition switch.
6. With the scan tool, read ABS DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the Stored Lost Communication DTCs diagnostic procedure. Stored Lost Communication DTCs.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

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

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

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

Yes

- Diagnose and repair the DTCs.

No

- Go To 3

3. VERIFY THAT THE TCM IS ACTIVE ON THE BUS
1. With the scan tool, select ECU View.

NOTE: For 545 RFE Transmission applications, the TCM is internal to the NGC4A.

2. Verify that the TCM is active on the bus.

Is the TCM active on the bus?

Yes

- Go To 4

No

- Perform the Stored Lost Communication DTCs diagnostic procedure. Stored Lost Communication DTCs.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

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

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

Yes

- Replace/update the Transmission Control Module (TCM). Transmission Control Module - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Replace the Anti-lock Brake System (ABS) Module. Anti-Lock Brake System Module - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.