Conditions for Setting the DTC
WARNING: This page is about a different car, the 2013 GMC Acadia, 2013 Chevrolet Traverse, and 2013 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects either a low voltage signal on the brake applied signal circuit when the serial data message from the BCM indicates the brakes are applied, or a high voltage signal on the brake applied signal circuit when the serial data message from the BCM indicates the brakes are not applied.