MillerOBD

Reference

Trouble code lookup

Type the code your scanner showed you. Codes start with a letter — P, B, C or U — followed by four characters.

Enter a code exactly as your scanner shows it, like P0420 or U0100.

The code library is being written

We are writing these pages properly — what the computer is actually measuring, what you will notice as a driver, and which causes are worth checking first — rather than dumping a definition table. The first batch covers the codes people search for most.

In the meantime, DriveDecode reads and explains every one of them from your car directly. See how it works.

What the first letter tells you

Every trouble code starts with a letter for the system that set it.

P

Powertrain

Engine, fuel, ignition, emissions and transmission.

B

Body

Interior systems — climate, lighting, restraints.

C

Chassis

Braking, steering and suspension systems.

U

Network

Communication between the modules in the car.

Only P codes are guaranteed

Generic OBD-II gives every scanner access to powertrain and emissions data. B, C and U codes usually need manufacturer-specific decoding, so a generic adapter — including the V015 — will often not see them at all. The definitions here explain those codes; reading them off your car is a different problem.

Generic and manufacturer-specific codes

A code like P0420 is generic: it means the same thing on a Honda as it does on a Ford, because the standard defines it. Codes in the P1xxx range are manufacturer-specific, and the same number means genuinely different things on different makes.

This matters more than most sites admit. Around a fifth of all trouble codes carry more than one published meaning, and reading the wrong manufacturer's definition sends you to the wrong part of the car. Where a code has multiple meanings, we list them by make rather than picking one.