GM Service Manual Online
For 1990-2009 cars only

Power Door Locks System Components

The power window system consists of the following components:

    • Body Control Module.
    • Driver door lock switch.
    • Passenger door lock switch.
    • Power door lock actuators in each door.
    • COURTESY Fuse 8 20A.

Power Door Locks System Controls

The power door locks system can be controlled by any of the following:

    • The Body Control Module controls the power to the door lock actuators.
    • A door lock switch activation.
    • An input to the BCM from the keyless entry transmitter. Refer to Keyless Entry System Description and Operation in Keyless Entry for more information about the Keyless Entry System.

Important: The power door locks are controlled by the body control module (BCM). The BCM also allows the door locks to operate for 35 seconds after exiting the vehicle and closing the doors. The door locks are enabled whenever either door is open unless the ignition key is in the ignition and the lockout prevention feature is enabled.

Both door lock actuators lock or unlock when either door lock switch is pressed. The locks are operated by reversible actuators. The door lock switches operate the actuators by applying a ground input signal to the BCM. The BCM then commands the actuators to lock or unlock. When the passenger door lock switch or the driver door lock switch is moved to the lock position, ground is applied to the BCM lock input through the Driver Door Lock Switch Lock Signal circuit. The BCM then applies battery voltage to both actuators through the Door Lock Actuator Lock Control circuit. The actuators are grounded by the BCM through the Driver Door Lock Actuator Unlock Control circuit and through the Passenger Door Lock Actuator Unlock Control circuit. When the passenger door lock switch or the driver door lock switch is moved to the unlock position, ground is applied to the BCM unlock input through the Driver Door Lock Switch Unlock Signal circuit. The BCM applies battery voltage to the actuators through the Driver Door Lock Actuator Unlock Control circuit and through the Passenger Door Lock Actuator Unlock Control circuit. Both of the actuators are grounded by the BCM through the Door Lock Actuator Lock Control circuit. Ground is supplied directly to the BCM.

Door Lock Feature Customization

The body control module (BCM) can be programmed to customize the power door locks operation. The 2 programmable functions are described below.

Last Door Closed Locking

The last door closed locking feature allows delayed door locking on all vehicles equipped with power door locks. This feature assures that all vehicle doors are locked after the driver and all passengers have exited the vehicle. When the driver door lock switch is pressed, an audible warning tone sounds 3 times to indicate that the last door closed locking function is initiated. The doors lock automatically 3 seconds after both doors are closed. Pressing the door lock switch to the unlock position after the warning tones cancels the last door closed locking function. Pressing the door lock switch to the lock position twice locks the doors immediately. The last door closed locking function does not work if the ignition key is in the ignition switch and the lockout prevention feature is enabled. The last door closed locking feature is disabled from the factory. Refer to Vehicle Personalization in Personalization for information on enabling the last door closed locking feature.

Lockout Prevention

The lockout prevention feature prevents the driver from locking the ignition key in the vehicle. The power door locks are disabled with the ignition key in the ignition and a door open. When the door lock switch is pressed with a door open an audible warning sounds five times as a reminder to remove the ignition key. The lockout prevention feature is disabled from the factory. Refer to Vehicle Personalization in Personalization for information on enabling the lockout prevention feature.