B1370 01

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Ignition 1 voltage circuit is shorted to voltage for more than 2 seconds.

B1370 06

Ignition 1 voltage circuit is open for more than 2 seconds.
Ignition 1 voltage, accessory voltage, or off/run/crank voltage circuit shorted to ground.
Battery positive voltage circuit of the ignition switch open or shorted to ground.
Run crank relay coil control circuit open (including relay coil and ground).