Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) supplies voltage to the HVAC module and the windshield washer solvent heater (RPO XA7), and the control circuit of the RUN PCB relay (TP2) through the ignition 3 voltage circuit. voltage is applied when any of the following conditions are true:
- Ignition Switch is in ACC or RUN.
- The vehicle was remote started.
- The vehicle is in retained accessory power (RAP) mode.