Power Liftgate Latch - Operation

OPERATION

The power cinching liftgate latch actuator motor (cinch/release motor) provides the torque required to close the liftgate from the secondary to the primary closed and latched position. The actuator also releases the liftgate from the primary closed and latched position to the fully unlatched and movable position. The actuator motor includes a small drive gear that meshes with the internal gear mechanism of the latch assembly to drive the latch and perform the power cinch and release functions.

The latch actuator is controlled by the Power Liftgate Module (PLGM) (also known as the Power Liftgate/PLG control module), which controls the cinch and release functions and limits actuator current draw to protect the assembly. The PLGM also monitors the latch and latch pawl positions through hard wired inputs from the sector, primary ratchet and secondary ratchet switches integral to the latch. If the power liftgate pinch sensors are damaged or ineffective, the PLGM will disable the cinching function of the latch.

Following every cinch or release sequence, the power liftgate latch will return to a home or neutral position. If for any reason the latch is unable to return to the home position, the PLGM will sense this through the integral latch switch inputs and prevent the latch from releasing. If this condition exists, activation of the power liftgate using the front or rear switches, the exterior handle or the Remote Keyless Entry (RKE) FOB with Integrated Key (FOBIK) will result in a short, audible beep tone being issued from the power liftgate chime. This indicates that the Power Liftgate Latch Homing standard procedure must be performed. Programming and Relearning.

The hard wired input and output circuits of the power liftgate latch may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls that provide some features of the power liftgate system. The most reliable, efficient and accurate means to diagnose the power liftgate latch or the electronic controls related to operation of the power liftgate system requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.