Chevrolet MONTE CARLO 1998 Manual page 67

Operation
Press UNLOCK once to
unlock the driver's door.
Press UNLOCK again
within five seconds to
unlock all remaining doors.
Pressing UNLOCK will
also cause the vehicle's
interior lamps to come
on for a period of time.
(See "Sustained Interior
Illumination" in the Index
for more details).
To lock both doors, press LOCK. To unlock the trunk,
press the trunk symbol on the transmitter. The trunk
will only unlock if your transaxle is in PARK (P);
pressing LOCK or the trunk symbol will also cause the
vehicle's interior lamps to come on for a period of time.
(See "Sustained Interior Illumination" in the Index
for more details).
Matching Transmitter(s) To Your Vehicle
Each remote keyless entry transmitter is coded to
prevent another transmitter from unlocking your vehicle.
If a transmitter is lost or stolen, a replacement can be
purchased through your dealer. Remember to bring any
remaining transmitters with you when you go to your
dealer. When the dealer matches the replacement
transmitter to your vehicle, any remaining transmitters
must also be matched. Once your dealer has coded the
new transmitter, the lost transmitter will not unlock your
vehicle. Each vehicle can have only four transmitters
matched to it.
Battery Replacement
Under normal use, the battery in your remote keyless
entry transmitter should last about three years.
You can tell the battery is weak if the transmitter won't
work at the normal range in any location. If you have to
get close to your vehicle before the transmitter works,
it's probably time to change the battery.