Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- A short to ground in the run/crank ignition circuit of the run crank relay will cause an open fuse to the ignition switch. DTC B1428 should be current.
- A short to ground in the accessory wakeup serial data circuit will cause an open fuse to the ignition switch. DTC U1814 should be current.
- The power modes and controls are determined using BCM logic. Comparing the Body Control Module Power Mode data display parameters listed in Circuit/System Verification will determine if there is a power mode fault.