Symptoms-Data Link Communications: Intermittent
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS .