Circuit/System Description
WARNING: This page is about a different car, the 2017 GMC Yukon XL, 2017 GMC Yukon, 2017 Chevrolet Tahoe, 2017 Chevrolet Suburban 3500 HD, and 2017 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
This is an internal fault detection of the control solenoid valve assembly. This fault is carried out inside the Transmission Control Module and no external circuits are involved.