Lockout Prevention
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.
This feature prevents the locking of the driver door if the ignition key is left in the ignition lock cylinder. If a lock function occurs from any door lock switch and the body control module (BCM) senses an active state on either the left front door latch signal, secondary door latch switch signal and the key in ignition switch signal circuit is in the YES state, the BCM, driver door switch (DDS) and passenger door switch (PDS) will lock the doors and then the DDS will unlock the driver door.