Power Liftgate System

POWER LIFTGATE SYSTEM

In order to obtain conclusive testing of the power liftgate system, the Controller Area Network (CAN) data bus, and all of the electronic modules that provide inputs to, or receive outputs from the power liftgate system components must be checked. Any diagnosis of the power liftgate system should begin with, the use of a scan tool and the appropriate diagnostic service information.

Refer to the appropriate wiring information for complete circuit schematic or connector pin-out information.

NOTE: Before any testing of the power liftgate system is attempted, the battery should be fully-charged.

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

- Using the scan tool, perform the "Latch Home Position Test"
- If the "Latch Home Position Test" is unsuccessful, disconnect the battery for 60 seconds. Reconnect the battery and grab the outside handle switch and hold it for at least 20 seconds
- If the latch still will not release, use the scan tool and select "Actuates", "Latch Motor Release Direction". This will drive the motor longer than just using the outside handle switch
- If driving the latch by the "Latch Motor Release Direction" worked, perform the "Latch Home Position Test" before returning the vehicle back to the owner. If driving the latch by the "Latch Motor Release Direction" did not work, use the following procedure to open the liftgate and continue diagnosis as necessary.


















POWER LIFTGATE SYSTEM INHIBITORS

The power liftgate system is designed with a number of system inhibitors. These inhibitors are necessary for safety and feasibility of the power liftgate system. Refer to power liftgate system inhibitors noted below:

- The Power Liftgate module will inhibit operation of the power liftgate in extreme temperatures. These temperatures will be approximately -22° F (-33° C) and 149° F (65° C). The pinch sensor/thermistor assembly on the right side of the liftgate monitors the temperature.
- The vehicle's transmission must be in park or neutral for the power liftgate to operate.
- The vehicle's speed must be zero for the power liftgate to operate.
- The vehicle's electrical system voltage must be within specification for the power liftgate system to operate. A low-voltage cut-off is built into the power liftgate system to prevent the vehicle's battery from discharging to the point were the vehicle cannot be operated.
- If the vehicle's ignition switch is in the "START" position, the power liftgate will pause.
- If multiple obstacles are detected during the same power open or close cycle, the liftgate will abort that power cycle and go into full manual operation.
- If severe Diagnostic Trouble Codes (DTC's) are stored in the power liftgate control module the system may not operate.

POWER LIFTGATE SYSTEM INHIBIT MONITORS

The following is a list of inhibit monitors as observed by an appropriate scan tool.