Buick 1994 Roadmaster Owner's Manual page 76

Rear Door Security Lock
Your Buick is equipped with rear door security, locks
that help prevent passengers from opening the rear doors
of your car from the inside. To use one of these locks:
The rear doors of your vehicle cannot be opened from
inside when this feature is in use. If you want to open a
rear door when the security lock is
on:
1. Unlock the door from the inside.
2. Then open the door from the outside.
older children who ride in the rear won't be able to open
2. Close the door.
the rear door from the inside. You should let adults and
3. Do the same thing to the older children know how these security locks work, and
1. Move the lever all the
way down. If you don't cancel the security lock feature, adults or
other rear door lock. how to cancel the locks.
To cancel the rear door lock:
1. Unlock the door from the inside and open the door
2. Move the lever all the way up.
3. Do the same for the other rear door.
from the outside.
The rear door locks will now work normally.