Circuit/System Description
WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
The power liftgate has a feature that detects the motion of a foot under the rear fascia, this allows the operator to open the liftgate when his or her hands are full of packages. As an indicator that the action has been properly preformed, the liftgate hands-free sensor control module will send a serial data message to the liftgate control module to command the liftgate to release and power open and the liftgate control module will send a serial data message to the body control module to command the tail lights to flash 3 times