Trunk / Liftgate: Description and Operation

Luggage Compartment Description and Operation

Rear Compartment Lid Release System Components

The rear compartment lid release system consists of the following components:

* Body control module (BCM)
* Folding top cover actuator
* GMLAN serial data link
* Keyless entry transmitter
* Rear compartment lid ajar switch
* Rear compartment lid release actuator
* Rear compartment lid release switch
* Remote control door lock receiver (RCDLR)
* Trunk fuses
* Trunk release relay
* Lift window Latch

Rear Compartment Lid Release System Operation

The rear compartment lid can be released by operating the rear compartment lid release switch or pressing the rear compartment lid release button on the keyless entry transmitter. When the rear compartment lid release switch is operated, the rear compartment lid release switch signal circuit to the body control module (BCM) is switched to ground. The BCM receives the rear compartment lid release switch input and applies ground to the trunk release relay control circuit. This energizes the trunk release relay coil, closing the switch side contacts, allowing battery voltage to be applied to the rear compartment lid release actuator and folding top cover actuator, releasing the buttresses and opening the rear compartment lid. Ground for the rear compartment lid release switch is provided at G300. The rear compartment lid ajar switch, rear compartment lid release actuator, and folding top cover actuator are provided ground at G301. The rear compartment lid will not release until the vehicle speed is zero and in park. For more detailed information concerning keyless entry refer to Keyless Entry System Description and Operation (Description and Operation).

The rear compartment lid release actuator and folding top cover actuator are remotely located in the forward area of the rear compartment on the left side. The rear compartment lid release actuator activates the rear compartment latch release with the use of a cable. When activated, the rear compartment lid release actuator pulls the cable, releasing the rear compartment latch. The folding top actuator operates in a similar manner, except that the two folding top release motors both pull in series on a single cable which activates both left and right buttress release mechanisms.

Trunk Ajar Indicator

The body control module (BCM) receives a discrete input from the rear compartment lid ajar switch signal circuit. When the trunk is opened, the normally open rear compartment lid ajar switch closes. With the rear compartment lid ajar switch closed, ground is provided to the rear compartment lid ajar switch signal circuit. 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 AJAR. If the trunk is still ajar and the vehicles speed is greater than 4.8 km/h (3 mph) a chime will sound.

Lift Window Release System Operation

The lift window can be released by operating the rear compartment lid release switch or by pressing the rear compartment lid release button on the remote keyless entry transmitter. The gear selector may be in any position, but the vehicle must be stationary for the lift window to release.

When the ignition is ON, the body control module (BCM) monitors the voltage to the rear compartment lid release switch through the trunk release switch supply voltage circuit. When the rear compartment lid release switch is operated, the trunk release supply voltage circuit is grounded through the switch ground circuit and the voltage is pulled low within the BCM. In response, the BCM applies ground to the trunk release relay control circuit, which energizes the coil side of the trunk relay. The switch side of the trunk relay then closes, supplying battery positive voltage through the relay and the latch motor voltage control circuit to the lift window latch. The latch then releases the lift window so that it may be manually raised to an open position.