Immobilizer Operation - GMC Cadillac XT4 2019 Owner's Manual

48 KEYS, DOORS, AND WINDOWS
To avoid setting off the alarm by
accident:
Lock the vehicle after all
occupants have left the vehicle
and all doors are closed.
Always unlock a door with the
RKE transmitter or use the Keyless
Access system.
Unlocking the driver door with the key
will not disarm the system or turn off
the alarm.
How to Detect a Tamper
Condition
If is pressed and the horn chirps
and the lights flash three times, the
alarm was activated while the alarm
system was armed.
If the alarm system has been
activated, a message will appear on
the DIC.

Immobilizer Operation

This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the vehicle is
turned off.
The immobilization system is
disarmed when the ignition is on or in
ACC/ACCESSORY and a valid
transmitter is present in the vehicle.
The security light, in the instrument
cluster, comes on if there is a problem
with arming or disarming the
theft-deterrent system.
The system has one or more RKE
transmitters matched to an
immobilizer control unit in your
vehicle. Only a correctly matched RKE
transmitter will start the vehicle.
If the transmitter is ever damaged,
you may not be able to start your
vehicle.
When trying to start the vehicle, the
security light may come on briefly
when the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the vehicle will not change ignition
modes (ACC/ACCESSORY, on, off), and
the RKE transmitter appears to be
undamaged, try another transmitter.
Or, you may try placing the
transmitter in the front cupholder
located in the center console.
If the ignition mode will not change
with the other transmitter or in the
front cupholder, your vehicle needs
service. If the ignition does change
modes, the first transmitter may be
faulty. See your dealer who can service
the theft-deterrent system and have a
new RKE transmitter programmed to
the vehicle.