Conditions for Setting the DTC

WARNING: This page is about a different car, the 2007 Hummer H2. 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 not currently valid.
ROM code has failed Checksum test indicating that ROM data is not currently valid.
One or more ROM locations have failed operational test indicating that some portions of RAM are not functional.