Circuit/System Description
WARNING: This page is about a different car, the 2016 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition is ON, the body control module supplies a 12 V signal to the rear compartment lid unlatch switch through the trunk release switch signal circuit. When the interior rear compartment lid release switch is pressed, the voltage within the signal circuit is pulled low and in response, the body control module will energize the trunk release relay.