Circuit/System Description
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
The K219 Lighting Control Module provides the M40 Rear Compartment Lid Latch with signal circuit 1303. Ground is applied at all times to the M40 Rear Compartment Lid Latch. When the rear compartment lid is open, ground is applied to the K219 Lighting Control Module through signal circuit 1303. The K219 Lighting Control Module will send a serial data message to the driver information center to display the Trunk Open message.