Drivers Door Key Switch
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The drivers door key switch is an internal function of the driver door latch. The door key switch use's a discrete input to the BCM. The BCM utilizes this input to disarm the CTD system. Inserting a key and turning to the unlock position will disarm the CTD system.