Chevrolet 2002 Silverado 1500 Pickup Owner's Manual page 91

Child Security Locks (Crew Cabs)
(If Equipped)
With this feature, you can lock the rear side
doors so that 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.
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