B1178

DTC Troubleshooting: B1178

DTC B1178:

F-CAN Communication Circuit Error

1. Clear the DTCs with the HDS.

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

3. Check for DTCs with the HDS.

Is DTC B1178 indicated?

YES -

Go to step 4.

NO -

Intermittent failure, the F-CAN communication line is OK at this time. Check for loose or poor connections. If the connections are good, test the battery Testing and Inspection, and the charging system.�

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

5. Disconnect the gauge control module 36P connector.

6. Jump the SCS line with the HDS.

7. Disconnect ECM/PCM connector E (31P).

8. Disconnect the VSA modulator-control unit 47P connector.

9. Disconnect the TPMS control unit connector B (20P) ('07-08 models) or the TPMS control unit 20P connector ('09-11 models).

10. Check for continuity between body ground and gauge control module 36P connector terminals No. 28 and No. 29 individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 11.

11. Turn the ignition to ON (II).

12. Measure the voltage between body ground and gauge control module 36P connector terminals No. 28 and No. 29 individually.





Is there less than 0.2 V?

YES -

Repair a short to power in the wire.�

NO -

Go to step 13.

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

14. Reconnect the gauge control module 36P connector.

15. Turn the ignition switch to ON (II).

16. Clear the DTCs with the HDS.

17. Reconnect the appropriate connector to each control unit in the table one at a time. Wait for 6 seconds, then recheck for DTCs after each unit is reconnected.









Is DTC B1178 indicated with each individual unit reconnected?

YES -

Replace the control unit that was reconnected.�

NO -

Replace the gauge control module Service and Repair.�