B1556

DTC B1556: Automatic Lighting Control Unit Lost Communication with Multiplex Integrated Control Unit (MICU Message)

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A.

1. Clear the DTCs with the HDS.
2. Turn the ignition switch OFF, and then back ON (II).
3. Check for DTCs with the HDS.

Is DTC B1556 indicated?

YES - Go to step 4.

NO - Intermittent failure. The gauge control system is OK at this time. Check pinfits and connections.

4. Check for DTCs with the HDS.

Are DTCs B1055, B1157, B1255 and B1807 also indicated?

YES - Go to Multiplex Integrated Control Unit Input Test. MICU Input Test

NO - Go to Automatic Lighting Control Unit Input Test. Automatic Lighting Control Unit Input Test