Lock All Doors

WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.

Press the LOCK button in order to perform the following functions:

Lock all of the doors.
Immediately turn off the interior lamps.
Flash the headlamps.
Chirp the horn, if the LOCK button is pressed a second time within 5 seconds.