Circuit/System Description
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
As a security measure, a valet switch in the glove compartment is used to disable the rear compartment release system. When the switch is activated and the glove compartment locked, it will prevent unauthorized access to the rear compartment. The body control module (BCM) monitors the valet mode switch signal circuit and when the switch is activated, the BCM detects the drop in voltage and will disable the rear compartment release system.