Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Cadillac Escalade EXT. However, it is still accessible from the selected car via links, so may be relevant.
Engine ON, the scan tool Ignition voltage parameter should display between 12.5-14.5 volts.
- If the voltage is not within the specified value, test the ignition voltage circuit for an open circuit or short to ground.