Free trouble-code library

CHECK ENGINE LIGHT?
START HERE.

You don’t have to know cars to understand yours.

A trouble code is evidence, not proof that a particular part has failed. Start with the explanation, then decide what to check next.

Browse the library

We’re starting with a focused pilot. A code missing here may still be valid, including manufacturer-specific codes.

Library coverage does not mean UTH Scanner reads every code, vehicle or module. Check vehicle compatibility separately.