Cadillac 2016 CT6 Owner's Manual page 48

The vehicle is automatically
immobilized when the vehicle is
turned off.
The immobilization system is
disarmed when the pushbutton start
is activated to enter the ACC/
ACCESSORY mode or the ON/
RUN/START mode 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 the
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/
RUN/START, OFF), and the RKE
transmitter appears to be
undamaged, try another transmitter.
Or, you may try placing the
transmitter in the transmitter pocket
located in the center console. See
Key and Lock Messages 0 150.
If the ignition modes will not change
with the other transmitter, your
vehicle needs service. If the ignition
does change modes, the first
transmitter may be faulty. See the
dealer.
It is possible for the immobilizer
system to learn new or replacement
RKE transmitters. Up to eight
transmitters can be programmed for
the vehicle. To program additional
transmitters, see Programming
Keys, Doors, and Windows
Transmitters to the Vehicle under
Remote Keyless Entry (RKE)
System Operation 0 29.
Do not leave the key or device that
disarms or deactivates the
theft-deterrent system in the vehicle.
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