Diagnostic Trouble Code Priority
WARNING: This page is about a different car, the 2003 Dodge Intrepid, 2003 Chrysler Intrepid, 2003 Chrysler Concorde, and 2003 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.
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.
- Priority 0
This is a non-emissions related DTC. - Priority 1
One-trip failure of a two trip DTC for non-fuel system and non-misfire conditions. - Priority 2
One-trip failure of a two trip DTC for fuel system rich or fuel system lean condition, or misfire condition. - Priority 3
Two-trip failure for non-fuel system or non-misfire condition, or a matured one trip comprehensive component fault. - Priority 4
Two-trip failure for matured fuel system rich or fuel system lean and misfire condition, or a one trip catalyst damaging misfire.
Non-emission related failures have no priority. One-trip failures of two trip faults have low priority. Two-trip failures or matured faults have higher priority. One and two trip failures of fuel system and misfire monitor take precedence over non-fuel system and non-misfire failures.