What is the OBD diagnosis? How does the OBD diagnosis work? How to decipher a fault code?

What is the OBD diagnosis?

OBD Socket The On-Board Diagnostic system “OBD” emerged in the early 2000s and is equipped in most vehicles produced since then. It allows precise reading of fault codes via an “OBD2” socket or On-Board Diagnostic system.

How does the OBD diagnosis work?

The On-Board Diagnostic system, using various sensors that inform the vehicle's computer, allows the detection of fault codes. When these codes are present, they are indicated to the user by an indicator light on the dashboard known as the MIL (Malfunction Indicator Lamp).

How to decipher a fault code

Fault code The first letter indicates the family of the fault code:

P: Powertrain, meaning engine and transmission

C: Chassis

B: Body

U: Communication Networks

The first digit indicates whether the code is generic or not (green digit):

0: Generic fault

1: Manufacturer fault

The last three digits correspond to:

0, 1 and 2: for air/fuel mixture control

3: for ignition system

4: for auxiliary emission controls

5: for idle control system

How can the OBDclick Diagnostic Tool help? 


Understanding your car's operation and being able to identify potential issues is essential for maintaining its longevity and performance. OBD diagnosis enables you to swiftly and accurately pinpoint your vehicle's problems, thus saving you time and money.

With OBDclick, the diagnostic tool becomes more accessible than ever. Easy to use and compatible with a wide variety of vehicles, OBDclick allows you to read and interpret your car's fault codes with ease. With OBDclick, you can diagnose your car anytime, anywhere.

So, what are you waiting for? Be proactive in maintaining your vehicle. Discover how it can help you take care of your vehicle.