GM Service Manual Online
For 1990-2009 cars only

The vehicle is programmed so that when the doors are closed, the ignition is on and the shift lever is moved out of P (Park), all the doors will lock. The doors will unlock every time you stop the vehicle and move the shift lever back into P (Park).

If someone needs to exit the vehicle once the doors are locked, have that person use the manual lever or power door lock switch for the rear doors. When the door is closed again, it will not lock automatically. Use the manual lever or the power door lock switch to lock the door.

The power door locks can be programmed through the Driver Information Center (DIC). For more information on programming, see DIC Vehicle Customization.