B1906

DTC Troubleshooting: B1906

DTC B1906: Immobilizer-Keyless Control Unit Lost Communication With Gauge Control Module (A/T Message)

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. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC B1906 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections between the gauge control module and the immobilizer-keyless control unit.


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

6. Connect the HDS to the data link connector, then turn the ignition switch to ON (II).

7. Select the BODY ELECTRICAL menu, then enter the UNIT INFORMATION.

8. Check the condition of the gauge control module from the CONNECTED UNIT list.

Is NOT AVAILABLE indicated?
YES - Go to step 9.

NO - Go to step 10.


9. Do the gauge control module input test. Gauge Control Module Input Test

Are all inputs OK?
YES - Replace the gauge control module. Service and Repair

NO - Repair the faulty input, then recheck the DTCs.


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

11. Disconnect the gauge control module 32P connector.

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

13. Measure the voltage between gauge control module 32P connector terminals No. 16 and No. 32 and body ground.

Is there battery voltage?
YES - Go to step 14.

NO - Check the No. 1 (7.5 A) and the No. 20 (15 A) fuses in the under-dash fuse/relay box. If the fuse is blown, replace the fuse and recheck the DTCs. If the fuses are OK, repair an open in the wire between the under-dash fuse/relay box and the gauge control module.






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

15. Check for continuity between gauge control module 32P connector terminals No. 13 and No. 17 and body ground.

Is there continuity?
YES - Go to step 16.

NO - Repair open in the wire or poor ground (G501).






16. Disconnect immobilizer-keyless control unit 7P connector.

17. Check for continuity between immobilizer-keyless control unit 7P connector terminal No. 4 and the gauge control module 32P connector terminal No. 18.

Is there continuity?
YES - Replace the gauge control module. Service and Repair

NO - Repair open in the wire.