Possible Causes

WARNING: This page is about a different car, the 2004 Dodge Intrepid, 2004 Chrysler Intrepid, 2004 Chrysler Concorde, and 2004 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.

WIRING HARNESS INTERMITTENT
OPEN PCI BUS CIRCUIT AT THE DATA LINK CONNECTOR (DLC)
HIGH VOLTAGE ON THE PCI BUS CIRCUITS AT THE BCM CONNECTORS
MODULE (PCI BUS SHORT TO VOLTAGE)
PCI BUS CIRCUIT SHORTED TO VOLTAGE
LOW RESISTANCE TO GROUND ON THE PCI BUS CIRCUITS AT THE BCM CONNECTORS
MODULE (PCI BUS SHORT TO GROUND)
PCI BUS CIRCUIT SHORTED TO GROUND