GM Service Manual Online
For 1990-2009 cars only

Door Lock System Components

The power door lock system consists of the following components:

    • LF door lock switch.
    • RF door lock switch.
    • Rear door lock switch (utilities only).
    • Door lock relay.
    • Door unlock relay.
    • Driver door unlock relay (uplevel vehicles).
    • Body Control Module (BCM).
    • Reversible door lock actuators in each of the doors.
    • Contact plate assemblies (cargo doors)
    • MIR/LOCK 3A fuse (switch supply voltage).
    • DR LOCK 20A fuse (relay supply voltage).
    • UNLOCK 15A fuse (unlock supply voltage).
    • LOCK 15A fuse (lock supply voltage).

Each of the doors are equipped with a reversible door lock actuator that will lock or unlock the doors depending upon the polarity of the supply voltage. The polarity of the supply voltage is determined by the position of the door lock switches or a BCM command.

Vehicles equipped with cargo doors have contact plates that interrupt the circuits to the cargo doors with the cargo doors open. The cargo doors must be fully closed for the cargo door lock actuator to operate.