Circuit/System Verification
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.
- Ignition ON, observe the scan tool brake controls TBCM Relay Feedback Signal volts parameter. The reading should be between 4.8 - 5.2 volts.
- Ignition ON, observe the scan tool brake controls Trailer Brake Relay Command volts parameter. The reading should be battery volts.