GM Service Manual Online
For 1990-2009 cars only

All of the doors will lock automatically when you move your shift lever out of PARK (P). All doors will unlock automatically when the ignition is turned off while the shift lever is in PARK (P). If you prefer to have your doors unlocked automatically at any time, see Vehicle Personalization .

If someone needs to get in or out of the vehicle after the doors have been automatically locked, place the shift lever into PARK (P). Unlock all doors using the power door lock switch or unlock the door you want using the inside manual lever. If you have programmed the Automatic Door Locks to unlock the doors when the shift lever is shifted into PARK (P), then the doors will automatically unlock for you. See Vehicle Personalization for programming information.

If you don't want the doors to unlock automatically when you turn the ignition off, see Vehicle Personalization .