1999 Chevrolet Tahoe Owner's Manual - Page 75
1999 Chevrolet Tahoe Manual
Page 75 highlights
yellowblue On the passenger side of the rear cargo door or tailgate, there is a power lock switch which can be used to lock or unlock all of the doors. Child Security Locks (If Equipped) With this feature, you can lock the rear side doors so they can't be opened from the inside by passengers. On vehicles with cargo doors, if the rear cargo lock switch is pressed with the cargo doors open, all of the doors will lock five seconds after the cargo doors are closed. If the cargo doors are closed, the vehicle's doors will lock when a power door lock switch is pressed. Move the button up to engage the security feature. Move the button down to return the door locks to normal operation. Leaving Your Vehicle If you are leaving the vehicle, take your keys, open your door and set the locks from inside. Then get out, and close the door. 2-5