Power Liftgate System: Operation

WARNING: This page is about a different car, the 2004 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.

Battery voltage is supplied to the power liftgate system through a 40 amp fuse, located in the Integrated Power Module (IPM) assembly. With the push of a power liftgate open/close command switch (key fob or overhead console mounted), a signal is sent out on the PCI Data Bus circuit. This signal is detected at the Body Control Module (BCM). The BCM then adds system status and sends a signal out on the PCI Data Bus circuit to the power liftgate control module. The power liftgate control module then interprets the information to confirm safety requirements are met before applying power to the power liftgate motor to start a power cycle.

During a power liftgate open or close cycle, if the power liftgate control module detects sufficient resistance to liftgate travel, such as an obstruction in the liftgate's path. The control module will immediately stop liftgate movement and reverse the direction of travel to the full open or closed position. The ability for the power liftgate control module to detect resistance to liftgate travel is accomplished by the optical and pinch sensors.

The power liftgate control module has the ability to relearn. Anytime the liftgate is opened or closed using the automatic system, the module learns from its cycle. If a replacement power liftgate component is installed or a liftgate adjustment is made, the module will relearn the effort and/or time required to open or close the liftgate. This learn cycle can be performed with a Diagnostic Scan Tool, such as the DRB III® or with a complete cycle of the liftgate, using either one of the command switches. Refer to STANDARD PROCEDURE for detailed instructions.