OBD2 diagnostics from your phone
Updated
When the check engine light comes on, the car already knows what is wrong: it stored it as a code. The problem is reading it. With an adapter under twenty dollars and the app, your phone becomes the scanner and you read that code yourself, before anyone quotes you a price.
- 32
- supported manufacturers
- 11
- connection protocols
- 19,222
- codes in the catalog
Scanner capability, verified against the app local code catalog.
Why did the check engine light come on?
That light means the car computer detected something out of range and stored a fault code. It could be serious or it could be a dirty oxygen sensor; the light looks identical either way. The code is what tells them apart: a P0420 points at the catalytic converter, a P0300 at misfires. Without reading it, any quote you get is guesswork.
What do I need to scan my car?
An ELM327 adapter, available over Bluetooth or WiFi and inexpensive. It plugs into the OBD2 port, which on nearly every vehicle from 1996 onward sits under the steering wheel. Turn the car on, pair the adapter with your phone, and the app does the rest: it identifies the protocol, reads the stored codes and translates them.
Which makes does it support?
The catalog covers the generic OBD2 standard codes, which apply to any vehicle, plus manufacturer-specific codes, which are the ones a cheap scanner cannot read. It also handles the full protocol range — CAN, both J1850 variants, K-Line and the Volkswagen group system — so it does not stall on older cars or on European ones.
Is it useful for checking a car before buying?
It is one of the most useful things you can do. A seller can clear the codes right before showing it to you, but the scan also reveals the state of the system readiness monitors: if none of them have completed, the computer was reset recently. On a car that is supposedly perfect, that says a lot.
Frequently asked questions
Can I clear codes from the app?
Yes, but clearing a code does not fix the fault: if the cause is still there, the light returns. It is for confirming a repair worked, not for hiding a problem.
Does it work on very old cars?
The OBD2 standard has been mandatory since 1996 in the United States and since the early 2000s in most markets. Before that each manufacturer had its own system and an OBD2 adapter cannot talk to it.
Which adapter should I buy?
Any ELM327 with Bluetooth or WiFi works. WiFi ones usually connect on a fixed address, and Bluetooth ones pair like any other device.
Is the diagnostic saved?
The session stays on your phone and you can export it as a report. If the vehicle is listed on Conduce, that diagnostic can also attach to its history.
Read what your car is telling you
Plug in an OBD2 adapter and scan from the app, no workshop needed.