DTC Troubleshooting: B1168

DTC B1168:  Gauge Control Module Lost Communication with the ECM/PCM (ENG Messages)

1.Clear the DTCs with the HDS.

2.Turn the ignition switch OFF, and then back 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.

Are DTCs B1168, B1169, B1178, B1183 and/or B1187 indicated?


YES - Go to 5.


NO - Intermittent failure, the F-CAN communication line is OK at this time. Check for loose or poor connections. If the connections are good, check the battery condition and the charging system.n


5.Check for DTCs in the ECM/PCM or ABS.

Are any DTCs indicated?


YES - Troubleshoot the ECM/PCM or ABS.n


NO - Go to 6.


6.Perform the Gauge Control Module Input Test.

Are all inputs OK?


YES - Go to 7.


NO - Repair the faulty input then recheck for DTCs.n

7.Substitute a known-good gauge control module (tach).

8.Clear the DTCs with the HDS.

9.Turn the ignition switch to OFF and then back ON (II).

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

11.Check for DTCs with the HDS.

Are DTCs B1168, B1169, B1178, B1183 and/or B1187 indicated?


YES - Substitute a known-good ECM/PCM and retest. If the system/indication goes away, replace the original  ECM/ PCM.n


NO - The original control module (tach) is faulty; replace the gauge control module (tach).n