U0300 Internal control module software incompatibility
- System
- Network - modules not talking to each other
This is a standard code. It means the same thing on every make of vehicle.
What OBD2 FaultFinder shows for U03xx codes
The Full scan's Vehicle identity section reads the Calibration and Verification number (CVN) from the control module and saves them with the scan. The Trouble Codes screen names the code where the program has its standard name, and Look up a code works with no car attached and says whether a code is standard or manufacturer-specific.