Power Liftgate System: Description

The components of the power liftgate system are:

• Liftgate gear motor assembly
• Latch assembly
• Lift gear and rod
• Power liftgate control module
• Chime/thermistor
• Full open switch
• Engage actuator
• Pinch sensor
• Liftgate handle switch
• Overhead console switch
• Key fob switches. See Fig 1
• Pawl switch
• Ratchet switch

Fig 1: Key Fob

Courtesy of DAIMLERCHRYSLER CORP.

The power liftgate system has its own power liftgate control module, located on the vehicles left body D-pillar behind the trim panel. The power liftgate gear motor assembly is located just above the control module. The latch assembly is located in the bottom center of the power liftgate, below the exterior liftgate handle switch. The power liftgate full open switch, engage actuator, lift gear and rod are part of the liftgate gear motor assembly. The pawl and ratchet switches are part of the latch assembly. The pinch sensors are located along the right and left sides of the power liftgate, just above the body line. The liftgate handle switch is a power release switch and is located in the rear light bar assembly, just above the license plate. The overhead console switch is a power open and close command switch located in the vehicles overhead console.

Software technology has enabled the power liftgate control module to detect resistance to liftgate travel, which allows the power liftgate to stop and reverse direction anytime an obstruction is felt or any of the command switches are operated (only in closing direction). Battery voltage is supplied to the power liftgate system through a 40 amp fuse, located in the Integrated Power Module (IPM) assembly. If the power liftgate system develops a fault, the power liftgate can still be operated manually with a key, similar to a manual liftgate.

The power liftgate control module communicates on the Programmable Communication Interface (PCI) Bus Circuit. Therefore, the power liftgate control module can generate and store its own Diagnostic Trouble Codes (DTC). The vehicles Body Control Module (BCM) receives and supplies messages to the power liftgate control module via the PCI bus circuit. A diagnostic scan tool, such as the DRB III® or equivalent, is used to read and troubleshoot these DTCs. Refer to BODY DIAGNOSTIC PROCEDURES for a complete list of diagnostic routines.

For additional information, (Refer to ELECTRICAL/POWER DOORS - OPERATION) . Refer to appropriate SYSTEM WIRING DIAGRAMS article for complete circuit schematic or connector pin-out information.