PistonbookCheck engine light on? Read the code.
Plug a Bluetooth OBD2 adapter in under the steering wheel: Pistonbook reads the fault codes, explains them in plain English and can clear them. Free.
In shortA Bluetooth OBD2 adapter (ELM327 type) plugs into the car's diagnostic port. Pistonbook connects to it, reads the check engine light and the generic fault codes, and tells you what they mean. The feature is free and in testing on Android.
How does it work?
Plug in the adapter
Into the OBD port, often under the steering wheel. Pair it in your phone's Bluetooth settings.
Turn the ignition on
Without starting the engine. In Pistonbook, open the vehicle, menu ⋯, "OBD2 fault codes".
Read and understand
The light, stored and pending codes, with their explanation. Clear them if you want.
Which adapter should I choose?
A Bluetooth ELM327-compatible adapter. This one has been tested with Pistonbook.
Your adapter works with Pistonbook and is not on the list? Let us know and we will add it.
A feature in testing
Compatibility not guaranteed
Depending on the car and the adapter, reading can fail. Pistonbook is not responsible for an adapter that does not work or for what you do with a code. If it fails, the app offers to send the log, without serial number or address, so it can be fixed.
Clearing is not repairing
Clearing a code turns the light off, not the fault. If the problem is still there, it will come back. If in doubt, show the code to a mechanic.
OBD2 fault codes
Is my car compatible?
In Europe, every petrol car since 2001 and diesel since 2004 has an OBD2 port, and in the US every car since 1996. Pistonbook reads the generic codes, shared by all brands.
Does it work on iPhone?
Not yet. Reading uses the phone's Bluetooth, which Safari does not open to websites: it will come with the iPhone app and a BLE adapter.
Are all codes read?
The engine and emissions codes, the ones that turn the light on. Brand-specific codes (airbag, ABS, comfort) need the manufacturer's tools.
Is it free?
Yes. Reading codes costs nothing to run, so it stays free. Only the adapter has to be bought.
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