Diagnostic Trouble Codes (DTCs)

With OBD II, different DTC faults have different priorities according to regulations. As a result, the priorities determine MIL illumination and DTC erasure. DTCs are entered according to individual priority. DTCs with a higher priority overwrite lower priority DTCs.

Priorities

- Priority 0 -Non-emissions related trouble codes
- Priority 1 -One trip failure of a two trip fault for non-fuel system and non-misfire.
- Priority 2 -One trip failure of a two trip fault for fuel system (rich/lean) or misfire.
- Priority 3 -Two trip failure for a non-fuel system and non-misfire or matured one trip comprehensive component fault.
- Priority 4 -Two trip failure or matured fault for fuel system (rich/lean) and misfire or one trip catalyst damaging misfire.