AcuraLink Control Unit

DTC Troubleshooting: U0100

DTC U0100:

Gauge Control Module Lost Communication With ECM/PCM

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Start and run the engine for at least 5 seconds, then turn the engine off.

4. Check for DTCs with the HDS.

Is DTC U0100 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the F-CAN communication line is OK at this time. Check for DTCs in the ECM/PCM with the HDS. If F-CAN DTCs are present, check for loose or poor connections at the gauge control module and the ECM/PCM. If the connections are good, check the battery condition Battery Test and the charging system, then clear all DTCs.�

5. Check for DTCs in the ECM/PCM with the HDS.

Are any DTCs indicated?

YES -

Go to the ECM/PCM indicated DTCs troubleshooting, then recheck.�

NO -

Go to step 6.

6. Turn the ignition switch to LOCK (0).

7. Jump the SCS line with HDS.

8. Disconnect ECM/PCM connector A (49P).

9. Check for continuity between gauge control module 32P connector terminals No. 21 and No. 22 and ECM/PCM connector A (49P) terminals No. 4 and No. 3 respectively.





Is there continuity?

YES -

Substitute a known-good ECM/PCM Service and Repair, and recheck. If the indication goes away, replace the original ECM/PCM Service and Repair. If the DTC is still present, replace the gauge control module Service and Repair.�

NO -

Repair an open or poor connection in the wire between the ECM/PCM and the gauge control module.�