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.

Critical operational parameters stored in EEPROM have failed Checksum test indicating invalid data.
Masked ROM code has failed Checksum test indicating that masked ROM data is no longer valid.
ROM code has failed Checksum test Indicating that ROM data is no longer valid.
One or more ROM locations have failed operational test indicating that some portions of RAM are not functional.
Motor circuit test has indicated that one of the modules's relays is not able to make contact.