Chevrolet 1998 Express Van Owner's Manual page 80

1. Insert a dime in the slot between the covers of the
transmitter housing near the key ring hole. Remove
the bottom by twisting the dime.
2. Remove and replace the battery, positive side down.
3. Align the covers and snap them together.
4. Check the operation of the transmitter.
Synchronization
Synchronization may be necessary due to the security
method used by this system. The transmitter does not
send the same signal twice to the receiver. The receiver
will not respond to a signal it has been sent previously.
This prevents anyone from recording and playing back
the signal from the transmitter.
To resynchronize your transmitter, stand close to your
vehicle and simultaneously press and hold the
LOCK
and UNLOCK buttons on the transmitter for at least five
seconds. The door locks should cycle to confirm
synchronization. If the locks do not cycle, see your
dealer for service.
Your Doors and How'They Work
Front Doors
To open the door from the outside, pull the handle and
pull the door open.
To open the door from the inside, pull the lever toward
you and push the door open.