Diagnose a car is as simple as a child’s play


Thanks to an OBD2 blutooth device and a mobile application, CarDiag allows motorists to inspect and diagnose their cars very easily, independently and in a few seconds.

Diagnose your car

A secure and ultra accessible device



Easily connect your OBD2 device to your car, and access its state of health in a few seconds.



OBD2 devices are available for less than 10$

Car Makes


CarDiag is compatible with all makes of vehicles released from 2001.



No risk for vehicles and their manufacturer guarantees.

About our Mobile App



A 100% free, intuitive and multi-brand application

Coupled with any OBD Bluetooth device, the CarDiag mobile application allows motorists to diagnose the breakdowns of their vehicle and indicates the origin of the possible breakdowns in simple and easy to understand terms.

It also allows electronic faults to be detected and the engine warning light to be turned off.


Mobile App CarDiag

Key Figures

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Compatible cars


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Breakdowns detected


User manual


  • Buy your OBD2 Bluetooth Device (for less than 10$)
  • Install the CarDiag mobile app (Android)
  • Plug the CarDiag device into your Car’s diagnostic Port (often hidden under the steering wheel)
  • Connect your OBD2 device to your Android Smartphone : go to : Settings > Bluetooth > Connect to Bluetooth signal OBDII with the code 1234 (or 0000)
  • Run the CarDiag App : launch a diagnostic and easily check your vehicle’s health (battery, breakdowns, component wear, CO2 emissions, etc.).


Matthew C.


This app is seriously amazing if you got time to do the labour. I couldnt believe what i had stumbled into. This car diagnostics application is simply an amazing idea. Like opening pandoras book what next.

Colin D.

This app to me is my preferred one I do use some others for second opinions but this has got to be the easiest to use and it does what it says it does, that’s why I’ve given it 5 stars.​

Marko L.


Nice idea, useful for people who don’t much about cars, like myself :)​


Our Partners



Major player in personal and property insurance in France.



Autorigin provides vehicle history reports. 



C2A Garantie specialist in mechanical breakdown guarantee


The engine light or MIL (Malfunction Indicator Lamp) is a light on the dashboard of cars which indicates that a malfunction has been detected in the engine or the emission control system.

The check engine light flashing

The engine should be stopped as soon as possible as there is a risk of engine damage. The computer will switch the engine to “degraded” mode, limiting the engine speed to 3000 rpm for a petrol engine and 2000 rpm for a diesel engine.

The check light appears and disappears

This occurs if the fault is not detected for the next three consecutive cycles (1 cycle = starting + running + engine shutdown).

Engine light on

The check engine light remains on until the detected fault has been removed from the engine control unit. An electronic diagnosis then makes it possible to consult the fault code and helps to establish a diagnosis with a view to possible repair. Then the fault code can be cleared with the diagnostic tool.

No, it is impossible to clear the maintenance indicators. This operation is specific depending on the manufacturers. Only specific tools allow you to do this.

No, Cardiag can only diagnose engine and transmission faults. In the case of an ABS, Airbag or ESP warning lights, only a manufacturer’s suitcase is capable of making a diagnostic.

Auto technicians and owners use an OBD scanner device to understand the data the system gathers. It can provide data about your car’s air temperature, coolant, crankshaft and camshaft, position, road speed, and throttle as well as engine RPM…

All vehicles manufactured or imported are OBD compatible :
– In the United States since 1996
– In Europe (Gasoline since 2001, Diesel since 2003, LPG since 2001)

All OBD bluetooth scanner tools are compatible with the CarDiag app.

Yes, the Cardiag application will allow you to turn off the engine light on your dashboard.

Yes, the Cardiag application will allow you to read and erase the engine faults detected on your vehicle.

The OBD Port, is the location where you can plug in any OBD tool into the vehicle to pull vehicle information. It is also the primary location of tracking devices such as dongles as the port provides ongoing power to the device.

Diagnostic Trouble Codes or OBD2 Trouble Codes are codes that the car’s OBD system uses to notify you about an issue. … A vehicle stores the trouble code in it’s memory when it detects a component or system that’s not operating within acceptable limits. The code will help you to identify and fix the issue within the car.

The OBD port is usually located under the dashboard, beneath the steering wheel column this website allows you to find the OBD port in your car.

We do not recommend that you leave the scanner permanently connected to your car, as it may drain your battery.