OBD Codes List. OBD-II Trouble Code Lookup

Code or symptom

Enter a full code or a symptom. Press / to search. How to read a code

Results

P0420Catalyst System Efficiency Below Threshold (Bank 1)Check Engine LightPowertrain - Auxiliary Emissions Controls P0171System Too Lean (Bank 1)Check Engine LightPowertrain - Fuel/Air Metering P0300Random/Multiple Cylinder Misfire DetectedCheck Engine LightPowertrain - Ignition P0430Catalyst System Efficiency Below Threshold (Bank 2)Check Engine LightPowertrain - Auxiliary Emissions Controls P0128Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)Check Engine LightPowertrain - Fuel/Air Metering P0087Fuel Rail/System Pressure - Too LowCheck Engine LightPowertrain - Fuel/Air Metering

Start with your code

Look up the code from your scanner to see what it means and what to check first. This list covers 9,414 generic OBD-II codes. Make-specific codes are on the Ford, Chevy, Toyota and Honda sites below.

Read the full code

Enter all five characters, including the letter. You can also search a symptom, such as rough idle. For older vehicles, use the OBD-I list linked below.

Before buying parts

A code points to a fault, not a shopping list. Read the checks and source notes before choosing a repair. Pages with only system-level guidance are marked in the results.

Code families

Guides

How to Read OBD-II Codes: P, C, B, and U Families Read OBD-II codes: the P, C, B, and U families, how the digits work, stored versus pending versus permanent, freeze frame, and the 1996 rule.