DTC B1406 (3-3): OnStar Control Unit Lost Communication with Driver's MPCS Unit (Door Look Switch Message): Notes
WARNING: This page is about a different car, the 2006 Acura RL and 2005 Acura RL. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see
TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
).