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Home >> GMC >> 2006 >> Sierra 1500 HD, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 912 (Theft Deterrent System) >> Diagnostic Information and Procedures >> Content Theft Deterrent (CTD) Does Not Disarm with Key Lock >> Circuit/System Description

Circuit/System Description

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The content theft deterrent (CTD) system is a software based system in which the body control module (BCM) actively monitors certain inputs to determine if unauthorized vehicle access is being attempted. The driver door lock cylinder switch is used as an input to disarm the CTD system. The driver door module (DDM) monitors the driver door key switch signal circuit to determine if the driver door cylinder is being rotated, indicating a vehicle key is being used to unlock the vehicle and the CTD system should be disarmed. The door key cylinder switch, located in the door latch assembly, provides a switched ground for the signal circuit. The DDM communicates the status of the driver door key switch to the BCM via serial data.