Chevrolet 1999 Cavalier Owner's Manual page 69

Power Door Locks (If Equipped)
Push the lower portion of the switch to lock your doors.
Push the upper portion of the switch to unlock your doors.
The lever on each rear door works only that door's lock.
It won't lock (or unlock) all of the doors
safety feature.
You can lock or unlock all
doors of your vehicle from
the driver's or front
passenger's door lock
switch.
--
that's a
Rear Door Security Lock (4-Door Models)
To Use One of These Locks
1. Use a key to move the lock all the way up.
2. Close the door.
3. Do the same thing to the other rear door lock.
The rear doors of your vehicle cannot be opened from
the inside when this feature is in use.
yellowblue
Your vehicle is equipped
with rear door security
locks that help prevent
passengers from opening
the rear doors of your
vehicle from the inside.
2-5