Description And Operation
DESCRIPTION
The Power Liftgate Module (PLGM) (1) has the responsibility of authorizing the power liftgate operation requests. The PLGM is located in the driver rear cargo area behind the D-pillar. The PLGM incorporates the chime buzzer.
OPERATION
Battery voltage is supplied to the PLGM through a fused B (+) fuse in the Power Distribution Center (PDC) so the PLGM can operate regardless of the ignition switch status.
The PLGM monitors many hard wired switch and sensor inputs from the liftgate latch and cinch mechanisms, the Power Drive Unit (PDU), the D-pillar power liftgate switch, the exterior latch handle power liftgate switch, the overhead console power liftgate switch and both pinch sensors.
The PLGM also confirms safety requirements are met before supplying power to the PDU to begin any power cycle.
The PLGM software detects obstructions through inputs from the two pinch sensors as well as by monitoring the resistance to travel of the PDU. When a sufficient obstruction is detected, the PLGM will reverse the direction of the liftgate. Also, an exterior liftgate handle pull during an automatic Close cycle will reverse the power liftgate operation to Open , while an exterior liftgate handle pull during an automatic Open cycle will cancel the cycle and put the power liftgate into full manual operation.
The PLGM also monitors many electronic message inputs received over the Controller Area Network (CAN) data bus network. Electronic message inputs include: ignition switch status, Transmission Range Sensor (TRS) status, vehicle speed, Remote Keyless Entry (RKE) commands, vehicle theft alarm status, power lock system status and (if equipped) liftgate flip-up glass ajar switch status. In response to those many inputs, the PLGM logic allows it to properly control numerous hard wired outputs that operate the power liftgate latch and cinch mechanisms and the PDU that opens and closes the liftgate as well as the chime tone generator that provides audible indications of the power liftgate status. The PLGM will also place electronic messages on the CAN data bus indicating the liftgate status and many of the hard wired sensor inputs it receives for use by other electronic modules in the vehicle.