Lock All Doors

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Press the transmitter LOCK button to perform the following functions:

Lock all vehicle doors.
Immediately turn OFF the interior lamps.
Flash the exterior lights, if enabled through personalization.
Chirp the horn, if enabled through personalization.
Arm the CTD system, if equipped.