Circuit Description
WARNING: This page is about a different car, the 2005 GMC Canyon and 2005 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
The electronic brake control module (EBCM) is wired to the ignition 1 voltage circuit to indicate the ignition ON/OFF state. The EBCM monitors this voltage and the voltage on the front wheel speed sensor voltage supply circuits to ensure that the voltages remain within an acceptable operating range. The EBCM cannot operate properly when the system voltage is too low.