GM Service Manual Online
For 1990-2009 cars only

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

If someone needs to get out while your vehicle is not in PARK (P), have the person use the power door lock switch. When the door is closed again, the doors will lock either when your foot is removed from the brake or the vehicle speed becomes faster than 3 mph (5 km/h).

With the vehicle in PARK (P) and the engine running, the door locks can be programmed through prompts displayed on the Driver Information Center (DIC). These prompts allow the driver to choose various lock and unlock settings. For programming information, see DIC Vehicle Personalization .