Circuit/System Description
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. 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 ignition 1 voltage 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.