Download Power Door Locks Inoperative Diagnostic Instructions • Perform the Diagnostic System Check – Vehicle prior to using this diagnostic procedure. • Review Strategy Based Diagnosis for an overview of the diagnostic approach. • Diagnostic Procedure Instructions provides an overview of each diagnostic category. Diagnostic Fault Information Circuit Switch Side Supply Voltage Relay Door Lock/Unlock Signal Door Latch Control Driver Door Lock Switch Ground Passenger Front Door Lock Switch Ground BCM Ground 1. Door Lock Malfunction 2. Door Lock Switch Malfunction Circuit/System Description The DR LCK fuse supplies battery positive voltage to the body control module BCM for the door lock system. The BCM supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position, the reference voltage is taken directly to ground and the BCM senses 0.0 volts on the signal circuit.