Circuit/System Description
WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
The transfer case normally operates in 2WD mode. When all wheel drive (AWD) is requested, the transfer case control module sends 12 volts to the transfer case clutch coil via the clutch coil control circuit. This engages the transfer case clutch assembly through a ball and cam apply system. The transfer case clutch coil is controlled by a high and low side driver. Both circuits must be activated to engage the system.