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 the Checksum test, indicating invalid data.
The masked ROM code has failed the Checksum test, indicating that masked the ROM data is no longer valid.
The ROM code has failed the Checksum test, indicating that the ROM data is no longer valid.
One or more ROM locations have failed the operational tests, indicating that some portions of RAM are not functional.
The motor circuit test has indicated that one of the modules's relays is not able to make contact.