B1370 06

WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

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
B+ circuit of the ignition switch open or shorted to ground
Run crank relay coil control circuit open, including relay coil and ground