B1959

DTC Troubleshooting: B1959

DTC B1959: Rear MICU Lost Communication with Relay Control Module (RM 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 ON (II).

3. Wait for more than 6 seconds.

4. Check for DTCs with the HDS.

Is DTC B1959 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections between the rear MICU and the relay control module.


5. Check for DTCs with the HDS.

Are DTCs B1005, B1058, B1959, B2162, and/or B2970 all indicated?
YES - Do the relay control module input test. Relay Control Module Input Test

NO - Do the rear MICU input test. Rear MICU Input Test