Circuit/System Description
WARNING: This page is about a different car, the 2008 Pontiac Torrent and 2008 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) monitors the signal circuit voltage. If the voltage level is too high, damage may result in the system. When a high voltage condition is detected, the BCM will ignore the switch command.