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OBD-II trouble code lookup

Type the code from your reader. You get the plain meaning, the common causes, and whether you can keep driving.

General guidance. Your owner's manual wins. If a red warning light is on or the car drives differently, stop safely and get help.

How to read a code

CharacterWhat it tells you
First letterThe system: P powertrain, B body, C chassis, U network
First digit0 is a generic code that means the same on every car. 1 is the carmaker's own
The restThe area and the exact fault

All 213 codes

Grouped by what they're about. The 150 most searched have a page of their own.

Variable valve timing Fix it soon

Cam and crank timing Stop driving

Oxygen sensor heater Fine to drive

Oxygen sensor Fine to drive

Fuel pressure and fuel pump Fix it soon

Mass air flow sensor Fix it soon

Manifold pressure sensor Fix it soon

Intake air temperature sensor Fine to drive

Coolant temperature sensor Fix it soon

Thermostat Fine to drive

Throttle and pedal position Fix it soon

Fuel mixture too lean Fix it soon

Fuel mixture too rich Fix it soon

Fuel trim after the catalytic converter Fine to drive

Fuel injector circuit Fix it soon

Engine overheating Stop driving

Cooling system performance Fix it soon

Transmission overheating Stop driving

Engine overspeed Fine to drive

Turbocharger boost Fix it soon

Engine misfire Fix it soon

Crankshaft position relearn Fine to drive

Crankshaft position sensor Fix it soon

Camshaft position sensor Fix it soon

Knock sensor Fine to drive

Ignition coil circuit Fix it soon

Exhaust gas recirculation Fine to drive

Secondary air injection Fine to drive

Catalytic converter efficiency Fine to drive

Evaporative emissions (fuel vapor) Fine to drive

Fuel level sensor Fine to drive

Cooling fan Fix it soon

Vehicle speed sensor Fix it soon

Idle control Fine to drive

Oil pressure sensor Fix it soon

Air conditioning pressure sensor Fine to drive

System voltage and charging Fix it soon

Brake light switch Fix it soon

Engine computer Fix it soon

Automatic transmission Fix it soon

Diesel particulate filter Fix it soon

Diesel exhaust fluid system (SCR) Fix it soon

Hybrid battery Fix it soon

Module communication Fix it soon

Wheel speed sensor Fix it soon

Questions

Where do I get the code?

A basic OBD-II code reader costs about as much as a tank of gas and plugs in under the dashboard. Many parts stores will read the code for you for free.

Does the code tell me which part to replace?

No. A code tells you what the computer noticed, not why. A lean code can be a cracked hose, a dirty sensor or a weak pump. Test before buying parts.

What about P1 codes?

Codes starting P1, and most B, C and U codes, are set by each carmaker and mean different things on different cars. Look those up for your make.

Can I just clear the code?

You can, but the cause is still there and the light will come back. Clearing also resets the readiness checks an emissions test looks for.

Track this automatically in Tagwell Auto

Tagwell Auto keeps your car's service dates and mileage, so when a code shows up you know what was done last. With a Bluetooth reader for the car's diagnostic port (called OBD-II), the phone app reads and clears trouble codes itself.

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