B1178

DTC B1178: F-CAN Communication Line Error

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

DTC B1169: Gauge Control Module Lost Communication with the PCM (A/T Messages)

1. Clear the DTCs using the HDS.
2. Turn the ignition switch OFF then back to the ON (II).
3. Start and run the engine for at least 5 seconds then turn the engine off.
4. Check for DTCs using the HDS.

Is DTC B1178, B1168 and/or B1169 indicated?

YES - Go to step 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.

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

Are any DTCs indicated?

YES - Troubleshoot the ECM/PCM, ABS/TCS or Navigation DTCs.

NO - Go to step 6.

6. Perform the Gauge Control Module Input Test. Gauge Control Module Input Test
- '03-05 models
- '06-07 models

Are all inputs OK?

YES - Go to step 7.

NO - Repair the faulty input then recheck for DTCs.

7. Substitute a known-good gauge control module.
8. Clear the DTCs using the HDS.
9. Turn the ignition switch OFF then back to the ON (II).
10. Start and run the engine for at least 5 seconds then turn the engine off.
11. Check for DTCs using the HDS.

Is DTC B1178, B1168 and/or B1169 indicated?

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

NO - The original gauge control module is faulty; replace the gauge control module.