Symptom Related Diagnostic Procedures

The power opening and closing power liftgate system is a complex system containing many components and modules. In order to obtain conclusive testing the Programmable Communications Interface (J1850) data bus network and all of the electronic modules that provide inputs to, or receive outputs from the power liftgate system must be checked.

The power liftgate system was designed to be diagnosed with an appropriate diagnostic scan tool, such as the DRB III. The most reliable, efficient, and accurate means to diagnose the power liftgate system requires the use of a DRB III scan tool and the proper Body Diagnostic Procedures. The DRB III can be used to observe various switch statuses throughout the power liftgate system to help the technician diagnose a defective switch or component. The DRB III can also be. used to actuate various components throughout the power liftgate system to help the technician diagnose a defective component.

Before any testing of the power liftgate system is attempted, the battery should be fully charged, all built-in power liftgate system inhibitors read and understood (Refer to power liftgate system operation) and all wire harness and ground connections inspected around the affected areas on the vehicle.

Liftgate System Diagnostic Chart (Part 1 Of 4):

Liftgate System Diagnostic Chart (Part 2 Of 4):

Liftgate System Diagnostic Chart (Part 3 Of 4):

Liftgate System Diagnostic Chart (Part 4 Of 4):

Following are quick reference diagnostic tables to help when diagnosing and testing the power liftgate system.