WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
Possible Causes
(G20) IGNITION SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
(G20) IGNITION SWITCH SENSE CIRCUIT SHORT TO (G900) IGNITION SWITCH SENSE RETURN CIRCUIT