iPhone · iPad · Android

The OBD2 app for iPhone and Android

Plug a Bluetooth ELM327 adapter into your car, read the check engine codes, watch live sensor data, and save what you find to the car's history or the project you're working on. Here's what it does, and which adapters actually connect.

Download for iOS Get it on Android Adapter compatibility

What the OBD2 scanner does

Trackara talks to your car through a standard ELM327 adapter. No second scanner app needed.

Read trouble codes

Pull the stored codes (DTCs) behind the check engine light, plus pending codes that haven't turned the light on yet.

Clear codes

Clear the codes after a repair. Clearing does not fix the fault; if it comes back, so does the code.

Live data

Watch sensor data such as engine RPM, coolant temperature and engine load, where your car and adapter support it.

Scan history

Past scans stay with the vehicle, so you can see whether a code is new or keeps coming back.

Codes on the project

Add a code to the project you're working on and turn it into a task, next to the parts and budget.

Every car in the garage

Unlimited vehicles, each with its own scan history and maintenance log.

ELM327 adapter compatibility

Most cheap OBD2 adapters are ELM327-based, but the connection type matters more than the brand. Buy by connection type for your phone.

Phone	Adapter type	Works?	Notes
iPhone / iPad	Bluetooth Low Energy ELM327 (sold as BLE, Bluetooth 4.0, or iOS compatible)	Yes	Connect from inside the Trackara app. You don't pair it in iOS Settings first.
iPhone / iPad	Classic Bluetooth ELM327 (older adapters, often pair with PIN 1234 or 0000)	No	iOS only lets apps use classic Bluetooth accessories that are Apple-certified, and generic ELM327 adapters aren't. This is an iOS limit, not a Trackara one.
Android	Classic Bluetooth ELM327	Yes	Pair the adapter in Android Bluetooth settings first, then choose it in Trackara.
Android	Bluetooth Low Energy only ELM327	Not yet	The Android app currently connects to classic Bluetooth adapters.
Both	Dual-mode adapter (classic Bluetooth and BLE)	Yes	The safest buy if you might switch phones.
Both	Wi-Fi ELM327	Not yet	The current apps connect over Bluetooth only.

Why live data depends on your adapter

Reading and clearing codes works on almost every ELM327 adapter. Live data is where they differ: some low-cost clones don't answer every command, respond slowly, or drop the connection. Your car also has to report a sensor for it to show up. So with some adapters you'll get codes but only part of the live data. If live data matters to you, buy a well-reviewed adapter rather than the cheapest one.

Which cars work

OBD2 is standard on cars and light trucks sold in the US from model year 1996, on petrol cars in the EU from 2001 and on diesel cars in the EU from 2004. The port is usually under the dash on the driver's side. New to this? Read how to read an OBD2 code, and look up terms in the car and OBD2 glossary.

How a code ends up on your project

Plug in the adapter with the ignition on (or the engine running).
Connect in Trackara. On iPhone the adapter shows up in the app's device list. On Android, pair it in Bluetooth settings first, then pick it in the app.
Scan. Stored and pending codes come back from the car.
Save it where it belongs. Add the code to the project you're working on and turn it into a task, so the fix, the parts and the cost stay together.
Clear after the repair and re-scan later to make sure it stays gone.

Questions

What is the best OBD2 app?

It depends on what you need. Dealer-level tools do more for specific brands. If you want to read and clear check engine codes, watch basic live data, and keep the codes with the car's maintenance history or a project, Trackara does that on iPhone, iPad and Android with a standard ELM327 adapter.

Is there a free OBD2 app for iPhone?

Trackara is free to download and free to try on iPhone. Keeping full access after that needs a subscription, billed through the App Store; the current price is shown there before you subscribe. You also need a Bluetooth Low Energy OBD2 adapter.

Does Trackara work with ELM327 adapters?

Yes. On iPhone and iPad it works with Bluetooth Low Energy ELM327 adapters. On Android it works with classic Bluetooth ELM327 adapters that you pair in Android settings. Dual-mode adapters work on both. Wi-Fi adapters are not supported in the current apps.

Why doesn't my ELM327 adapter show up on my iPhone?

It is probably a classic Bluetooth adapter. iOS only lets apps use classic Bluetooth accessories that are Apple-certified, so generic classic ELM327 adapters can't connect to any iPhone app. Use an adapter sold as Bluetooth LE, Bluetooth 4.0 or iOS compatible, and connect from inside the app rather than iOS Settings.

Why can't I see all the live data?

Live data depends on your Bluetooth OBD2 adapter and on which sensors your car reports. Some low-cost adapters don't support every command, so you may be able to read codes but see only part of the live data.

Can the app clear the check engine light?

Yes, it can send the clear-codes command. Clearing does not fix the problem, and it also resets the emissions readiness monitors, so don't clear codes right before an emissions inspection.

Which cars does an OBD2 app work with?

Cars and light trucks sold in the US from model year 1996, petrol cars in the EU from 2001 and diesel cars in the EU from 2004 have an OBD2 port. Most other markets followed in the 2000s.