B1056

DTC Troubleshooting: B1055, B1056

DTC B1055: Relay Control Module Lost Communication with MICU (MICU Message)

DTC B1056: Relay Control Module Lost Communication with MICU (ALARM 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 B1055 and/or B1056 indicated?
YES - Go to step 5.

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


5. Check for DTCs with the HDS.

Are DTCs B1157, B1255, B1605, B1806, B2107, and B2155 all indicated?
YES - Do the MICU input test. Multiplex Integrated Control System MICU Input Test

NO - Do the relay control module input test. Relay Control Module Input Test

DTC Troubleshooting: B1055, B1056

DTC B1055: Relay Control Module Lost Communication with MICU (MICU Message)

DTC B1056: Relay Control Module Lost Communication with MICU (ALARM 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 B1055 and/or B1056 indicated?
YES - Go to step 5.

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


5. Check for DTCs with the HDS.

Are DTCs B1157, B1255, B1605, B1806, B2107, and B2155 all indicated?
YES - Do the MICU input test. Multiplex Integrated Control System MICU Input Test

NO - Do the relay control module input test. Relay Control Module Input Test