2008 Cadillac CTS Owner's Manual - Page 106

Immobilizer Operation (Keyless Access) Your vehicle has a passive theft-deterrent system. The system is automatically armed when the ignition control knob is turned to LOCK/OFF. The immobilization system is disarmed when the ignition control knob is pushed in and a valid transmitter is found in the vehicle. You do not have to manually arm or disarm the system. The security light will come on if there is a problem with arming or disarming the theft-deterrent system. The system has one or more keyless access transmitters that are matched to an immobilizer control unit in your vehicle. Only a correctly matched keyless access transmitter will start the vehicle. If the keyless access transmitter is ever damaged, you may not be able to start your vehicle. When trying to start the vehicle, if the engine does not start and the security light comes on, there may be a problem with your immobilizer system. Turn the ignition control knob off and try again. If the ignition control knob does not rotate, and the keyless access transmitter appears to be undamaged, try another keyless access transmitter. Or, you may try placing the transmitter in the transmitter pocket located in the center console. See "Electronic Key Not Detected" under DIC Warnings and Messages on page 3-54. At this time, you may also want to check the fuse. See Fuses and Circuit Breakers on page 5-122. If the ignition control knob still does not rotate with the other transmitter, your vehicle needs service. If the ignition control knob does rotate, the first transmitter may be faulty. See your dealer/retailer who can service the theft-deterrent system and have a new keyless access transmitter programmed to the vehicle. It is possible for the immobilizer system to learn new or replacement keyless access transmitters. Up to 4 keyless access transmitters can be programmed for the vehicle. To program additional transmitters, see "Matching transmitter(s) to Your Vehicle" under Keyless Access System Operation on page 2-9. Do not leave the key or device that disarms or deactivates the theft deterrent system in the vehicle. 2-30