U03xx OBD-II Codes (U0300–U0399)
10 fault codes in the U03xx range. Click any code for causes, diagnostic steps, severity, and common fixes.
U0300 moderate
Internal Control Module Software Incompatibility
U0301 moderate
Software Incompatibility With ECM/PCM
U0302 moderate
Software Incompatibility With Transmission Control Module
U0303 moderate
Software Incompatibility With Transfer Case Control Module
U0304 low
Software Incompatibility With Cruise Control Module
U0305 moderate
Software Incompatibility With Body Control Module
U0306 low
Software Incompatibility With Instrument Panel Module
U0307 low
Software Incompatibility With HVAC Control Module
U0308 low
Software Incompatibility With Seat Control Module
U0309 low
Software Incompatibility With Auxiliary Heater Control Module