The CTD system (when armed) is designed to deter vehicle theft by pulsing the horns and the exterior lights when an unauthorized vehicle entry is detected. An unauthorized entry can be any of the following:

The remote function actuator module (RFA) controls all of the alarm functions. When the RFA has detected an unauthorized entry, the RFA applies ground to the horn relay and to the lamp control module (LCM) once per second for approximately 3 minutes or until a valid disarm input is received. The RFA has 5 basic modes for operating the CTD system:

1. Disarmed Mode -- The CTD system remains in the disarmed mode until the RFA detects all of the following conditions:

•	The ignition switch is turned to the LOCK position.

•	Any door is opened.

•	The doors are locked by pressing the power door lock switch or the keyless entry transmitter. (If all of the doors are closed and the transmitter is used in order to lock the doors the RFA enters the delayed mode.)

2. Standby Mode -- The CTD system enters the standby mode when the above conditions are detected. The RFA grounds CKT 264 (DK GRN) once per second and flashes the SECURITY indicator. When the RFA detects that all of the doors are closed, the CTD system enters the delayed mode.
3. Delayed Mode -- The CTD system enters the delayed mode for 30 seconds. The RFA grounds CKT 264 (DK GRN) and illuminates the SECURITY indicator. After 30 seconds the CTD system enters the armed mode.
4. Armed Mode -- The CTD system monitors all of the inputs for an unauthorized or a forced entry when in the armed mode. The RFA removes ground from CKT 264 (DK GRN) and the SECURITY indicator turns off. If forced entry is detected, the CTD system enters the alarm mode.
5. Alarm Mode -- The CTD system enters the alarm mode when a forced entry is detected while the CTD system is in the armed mode. The RFA grounds the horn relay CKT 28 (BLK/WHT) and the exterior lights control enable input CKT 624 (BLK/WHT) to the lamp control module (LCM) once per second for approximately 3 minutes, or until a valid disarm input is received. After 3 minutes the CTD returns to the armed mode.

The CTD system does not enter the armed mode if a door unlock request is received by the RFA during the arming sequence. The RFA then removes ground from CKT 264 and turns off the SECURITY indicator. The arming sequence must then be repeated. The CTD system can enter the armed mode with the vehicle's windows open.