Trunk / Liftgate: Description and Operation

POWER LIFTGATE

The power liftgate (PLG) feature allows the customer to automatically open or close the liftgate by activating the overhead console button, the remote keyless entry transmitter, lifting the exterior handle (open only) or activating the liftgate trim-mounted switch (close only). The PLG uses a power cinching system to latch the liftgate.

The PLG feature suspends a power open or power close when the ignition key is moved to the START position. The clutch will remain active to hold the liftgate in place during a start operation. Once the ignition key is no longer in the START position, the liftgate power open or power close will resume.

The overhead console on/off switch (shared with the power sliding door) disables operation from the liftgate handle, liftgate close switch and PLG control switch when in the OFF position.

The PLG system consists of the following components:
- PLG control switch (located in the overhead console)
- PLG close switch (located in the liftgate trim)
- Overhead console on/off switch
- PLG motor (located behind the LH rear quarter trim panel)
- Position sensor (located on the PLG motor assembly)
- Pinch strip switches (located on the body above the left and right taillamps)
- PLG latch (located in the middle lower portion of the liftgate)
- Forkbolt switches (located in the PLG latch)
- Detent switch (located in the PLG latch)
- Unlatch actuator (located in the PLG latch)
- Cinching motor (located in the PLG latch)
- Lock/unlock actuator (located in the PLG latch)
- PLG module (located behind the left rear quarter trim panel)

The PLG is controlled by the PLG module.

The PLG module receives inputs from:
- the forkbolt switch - primary (determines the position of the latch).
- the forkbolt switch - secondary (determines the position of the latch).
- the detent switch (determines the position of the latch).
- the PLG control switch (located in the overhead console).
- the PLG close switch (located in the liftgate trim).
- the overhead console on/off switch.
- the pinch strip switches (determines if an obstacle is between the pinch strip and liftgate).
- the position sensor (determines the direction, travel speed and obstacle detection of the liftgate).
- the ISO serial communication link.

The PLG module sends outputs to:
- the liftgate motor.
- the liftgate clutch.
- the cinching actuator.
- the unlatch actuator.
- the liftgate close chime.

The liftgate close chime provides the sounding of an audible chime (housed in a unit external from the PLG module) whenever a powered closing operation is initiated or if conditions are not correct for closing. The chime sound serves as a warning to alert the vehicle occupants and any bystanders that the liftgate is being moved in a closing direction by a powered operation. The PLG module controller will activate the external chime unit 's continuous chime mode through a discrete high side drive output signal. The output will be active for 3 seconds, resulting in the chime sounding for a period of 3 seconds. The gate will not be moved for the first second, as a pre-warning of impending gate movement.

The PLG may not operate under the following conditions:
- Low voltage or dead battery
- Disconnected battery
- PLG that has been left open for more than 6 hours
- PLG that has been manually closed and left ajar

If any of these conditions have occurred, the PLG must be reset before carrying out any pinpoint tests. Refer to Power Liftgate Initialization. Programming and Relearning