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 at the gauge control module (tach) 36P connector and at the immobilizer-keyless control unit 7P connector.


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

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

7. Check the condition of the gauge control module (tach) from the CONNECTED UNIT list.

Is NOT AVAILABLE indicated?
YES - Go to step 8.

NO - Replace the immobilizer-keyless control unit. Service and Repair


8. Do the gauge control module (tach) input test. Gauge Control Module (Tach) Input Test

Are all inputs OK?
YES - Go to step 9.

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


9. Disconnect the immobilizer-keyless control unit 7P connector.

10. Disconnect the gauge control module (tach) 36P connector.

11. Check for continuity between immobilizer-keyless control unit 7P connector terminal No. 4 and gauge control module (tach) 36P connector terminal No. 21.

Is there continuity?
YES - Replace the gauge control module (tach). Gauge Control Module Replacement

NO - Repair open in the wire between the immobilizer-keyless control unit and the gauge control module (tach).