2002 GMC Yukon Owner's Manual - Page 96

Lockout Prevention 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 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. Child Security Locks (If Equipped) With this feature, you can lock the rear side doors so they cannot be opened from the inside by passengers. Your vehicle may have one of the two child security lock labels shown. This feature is located on the inside edge of the rear doors. Move the lever forward to engage the security feature. Move the lever rearward to return the door locks to normal operation. 2-10