Rear Compartment Lid Release Operation
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
When the rear compartment lid release switch is pressed, the trunk release switch signal circuit is switched to ground. The BCM responds by applying battery voltage to the relay control circuit which energizes the relay. The relay is supplied with battery voltage at all times from the 10A fuse. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid latch causing the rear compartment lid to release. The rear compartment lid release switch is permanently grounded to a fixed body ground.