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Home >> Chevrolet >> 2002 >> Impala LS >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Theft Deterrent System >> Description & Operation >> Content Theft Deterrent System >> Body Control Module (BCM)

Body Control Module (BCM)

The CTD system is an internal function of Body Control Module (BCM) which utilizes class 2 serial data and various switch input information to perform CTD functions. When BCM detects an unauthorized entry, it activates horns and exterior lamps. BCM has five basic modes (disarmed, standby, delayed, armed, and alarm) for operating CTD system. BCM has CTD system in a disarmed mode until following conditions are detected:

The BCM enters standby mode when above conditions are detected. In standby mode, BCM commands SECURITY indicator to flash. If all doors are closed and LOCK button on RKE transmitter is used, BCM enters delayed mode.

When last door is closed, BCM enters delayed mode for 30 seconds. In delayed mode BCM commands SECURITY indicator to illuminate on steady.

After 30 seconds, BCM enters armed mode. Any forced entry activates alarm mode.

When BCM detects a forced entry, BCM enters alarm mode. BCM activates horns and exterior lamps for 2 minutes. This is followed by a three minute time-out with horn no longer active. If no new intrusions are detected after time-out, horn is not active. System must be disarmed or intrusion condition removed after time-out for system to exit alarm mode.