Guides

How to read your car’s fault codes yourself, what they mean for driving and inspections, and what you need to get started.

• Check engine light on: what it means and what to do

  The check engine light means the engine computer has found a fault and stored a code for it. The code tells you where to look, and how urgent it is.

• Clearing fault codes before an emissions test

  Clearing turns the check engine light off, but it doesn’t repair anything, and it resets the self-tests that inspections reading OBD check. Repair first, clear, then drive.

• Which ELM327 OBD2 adapter works in the browser

  Read My Car talks to an ELM327 adapter in the car’s OBD2 socket. Which adapter you need depends on the device you’ll use it with.

• Read OBD2 fault codes on an iPhone

  Safari on iPhone and iPad can’t use Bluetooth. Open Read My Car in the free Bluefy browser and connect a Bluetooth Low Energy adapter.

• Does my car have OBD2?

  As a rule, petrol cars from 2001 and diesels from 2004 in the EU (EOBD), and cars and light trucks from model year 1996 in the US, have OBD2. European cars that use the older, slower K-line protocols work too.

All explained fault codes