GM Service Manual Online
For 1990-2009 cars only

Door Locks without Keyless Entry

The door lock switches control the following power door lock features:

Unlock: The door lock switch unlocks all of the doors when you press UNLOCK on either door lock switch.

Lock: The door lock switch locks all of the doors when you press LOCK on either door lock switch.

Power Door Locks with Keyless Entry

The power door lock system can be operated in two different ways. The basic function is similar to the system without keyless entry. The door lock/unlock relay controls the power door locks with keyless entry. The body control module (BCM) operates the system with the transmitter. The door lock switches an also operate the system

The BCM has the following door lock features with keyless entry.

Lockout prevention: The BCM will not lock the doors if the key is in the ignition cylinder and the driver door is open.

Lockout prevention override: The BCM can override the lockout prevention and lock all of the doors. This feature occurs when you press and hold LOCK for at least three seconds.

Driver door unlock: The BCM locks the driver door when you press UNLOCK on the keyless entry transmitter.

Unlock: The BCM unlocks all of the doors when you press UNLOCK on the keyless entry transmitter again within 5 seconds of pressing unlock. The door lock switch unlocks all of the doors when you press UNLOCK on either door lock switch.

Lock: The BCM locks all of the doors when you press LOCK on the keyless entry transmitter. The door lock switch locks all of the doors when you press LOCK on either door lock switch.

Refer to Keyless Entry System Operation in Keyless Entry for more information about the keyless entry system.