Circuit/System Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) controls the Run/Crank relay through the run/crank relay coil control circuit by applying voltage to the circuit. The Run/Crank relay is energized when the ignition switch is in ON or START, or when a remote start is requested.