Conditions for Setting the DTC
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
At least one critical operating parameter has not been associated with an identification number within about 5 seconds after beginning class 2 serial data communication.