GM Service Manual Online
For 1990-2009 cars only

Automatic Locking

If your vehicle has an automatic transmission, all the doors and liftgate will automatically lock when the ignition is in RUN and the shift lever is moved out of PARK (P).

If your vehicle has a manual transmission, all the doors and liftgate will automatically lock when the vehicle reaches a speed of more than 3 mph (5 km/h).

All doors must be closed. The automatic locking feature cannot be disabled.

In the following situations, all doors will lock again when:

    • The brake pedal is applied, a door is opened and then closed, and the brake pedal is released, for a vehicle with an automatic transmission.
    • A door is opened and then closed while the vehicle is moving faster than 3 mph (5 km/h), for a vehicle with an manual transmission.

Programmable Automatic Unlocking

If your vehicle has an automatic transmission, all the doors and liftgate will automatically unlock when the shift lever is moved into PARK (P).

If your vehicle has a manual transmission, all the doors and liftgate will automatically unlock when the key is removed from the ignition.

The unlocking feature can be programmed on or off by turning the ignition to RUN, engine not running, and pressing the unlock part of the power door lock switch for eight seconds. The horn will chirp once when this feature is on and twice when it is off.