Chevrolet 1999 Monte Carlo Owner's Manual page 70

Resynchronization
Resynchronization may be necessary due to the security
method used by this remote keyless entry system.
The transmitter does not send the same signal twice
to the receiver. The receiver will not respond to a signal
it has previously been sent; this prevents someone
from recording and playing back the signal from
the transmitter.
To resynchronize the transmitter with the receiver, do
the following:
1. Stand close to your vehicle.
2. Simultaneously press and hold the LOCK and
UNLOCK buttons on the transmitter for about seven
seconds. The door locks should cycle (lock and
unlock) to confirm resynchronization.
If the locks do not cycle, see your dealer for service.
2-8
Trunk
CAUTION:
It can be dangerous to drive with the trunk lid
open because carbon monoxide (CO) gas can
come into your vehicle. You can't see or smell
CO. It can cause unconsciousness and even death.
If you must drive with the trunk lid open or if
electrical wiring or other cable connections must
pass through the seal between the body and the
trunk lid:
D
Make sure all other windows are shut.
D
Turn the fan on your heating or cooling
system to its highest speed with the setting
on VENT. That will force outside air into
your vehicle. See "Comfort Controls" in
the Index.
D
If you have air outlets on or under the
instrument panel, open them all the way.
See "Engine Exhaust" in the Index.
yellowblue