2008 GMC Yukon Owner's Manual - Page 110

Rear Door Security Locks Your vehicle has rear door security locks. These prevent passengers from opening the rear doors from the inside. The rear door security locks are located on the inside edge of each rear door. When you want to open a rear door when the security lock is on, do the following: 1. Unlock the door by lifting the rear door manual lock, using the power door lock switch, or the Remote Keyless Entry (RKE) transmitter, if the vehicle has one. 2. Open the door from the outside. To cancel the rear door security lock, do the following: 1. Unlock the door and open it from the outside. 2. Insert the key into the security lock slot and turn it so the slot is in the vertical position. Lockout Protection This feature protects you from locking the key in the vehicle when the key is in the ignition and a front door is open. Security Lock Label shown The rear doors must be open to access them. The label showing lock and unlock positions is located near the lock. To set the locks, do the following: 1. Insert the key into the security lock slot and turn it so the slot is in the horizontal position. 2. Close the door. 2-12 If the driver's side power door lock switch is pressed when the driver's door is open and the key is in the ignition, all of the doors will lock and then the driver's door will unlock. If the passenger's side power door lock switch is pressed when the front passenger's door is open and the key is in the ignition, all of the doors will lock and then the front passenger's door will unlock.