Circuit/System Description
WARNING: This page is about a different car, the 2013 GMC Yukon, 2013 Chevrolet Tahoe, and 2013 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
The hybrid powertrain control module compares the internal mode switch requested direction to other data to verify that the indicated direction range switch calculation is correct.