2003 GMC Sonoma Owner's Manual - Page 85

Rear Door Security Locks If you have the Crew Cab@model, your vehicle may be equipped with rear door security locks. With this feature, you can lock the rear doors so they can't be opened from the inside by passengers. The security lock lever is located on the inside edge of each rear door. To use the security locks, do the following: 1. Open one of the rear doors. 2. Slide the lever up to the lock symbol to engage the lock. 3. Close the door. 4. Repeat these steps on the opposite rear door. If you want to open the rear door when the security lock is on, unlock the door and open the door from the outside. To return the rear doors to normal use, disengage the locks by sliding the lever to the unlock symbol. Lockout Protection This feature protects you from locking your key in the vehicle when the key is in the ignition and a door is open. If the power door lock switch is pressed when a door is open and the key is in the ignition, all of the doors will lock and then the driver's door will unlock. 2-10