B1370 06

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.

Ignition 1 voltage circuit is open.
Ignition 1 voltage, accessory voltage, or off/run/crank voltage circuit shorted to ground.
B+ circuit of the ignition switch open or shorted to ground.
Run crank relay coil control circuit open (including relay coil and ground).