The interior rear compartment lid release switch receives a signal from the driver door switch assembly (DDSA). When the interior rear compartment lid release switch is activated, the signal circuit is pulled to ground. The DDSA interprets this and sends a GMLAN serial data message to the body control module (BCM) requesting the rear compartment lid be released. The BCM responds by applying battery voltage to the trunk release relay control circuit which energizes the TRUNK RELES relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The rear compartment lid release actuator is permanently grounded at G402.

The exterior rear compartment lid release switch receives a signal from the remote control door lock receiver (RCDLR). When the exterior rear compartment lid release switch is activated, the signal circuit is pulled to ground. The RCDLR interprets this and sends a GMLAN serial data message to the body control module (BCM) requesting the rear compartment lid be released. The BCM responds by applying battery voltage to the trunk release relay control circuit which energizes the TRUNK RELES relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The exterior rear compartment lid release switch is permanently grounded at G401.

When accessing the rear compartment using the key fob, a valid keyless entry transmitter is required to be within a 1 meter range of the vehicle. This allows the required keyless access communications to occur between the rear compartment antenna and the keyless entry transmitter. For more information about keyless access, refer to Keyless Entry System Description and Operation .

The body control module (BCM) receives a discrete input from the rear compartment lid ajar switch signal circuit. When the rear compartment lid release actuator releases the rear compartment lid, the rear compartment lid ajar switch, which is internal the rear compartment lid release actuator, is supplied with ground which causes the trunk ajar switch signal circuit to be pulled low. The BCM interprets this and communicates via GMLAN serial data with the instrument panel cluster (IPC). When the trunk is open/ajar and the vehicle is in any gear other than PARK, the driver information center (DIC) will display TRUNK OPEN. If the trunk is still open and the vehicles speed is greater than 4.8 km/h (3 mph) a chime will sound.