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