Circuit/System Description
WARNING: This page is about a different car, the 2011 GMC Cab & Chassis Sierra, 2011 Chevrolet Suburban, and 2011 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The solenoid relay, located within the electronic brake control module (EBCM), supplies battery voltage to all of the valve solenoids.