What is car diagnostics?

by | May 24, 2022 | Diagnostics

A car diagnostic test is a scan of your car’s components and systems to check for any issues. It is usually the first step used to identify issues with your car.

The onboard computer of modern cars collects lots of data from your journeys and creates reports that can be analysed during car diagnostic tests.

A diagnostic test report will not be able to tell the mechanic the exact problem but it will help them to narrow down the issue so that it can be fixed faster and give a general health check to your vehicle at the same time.

When should I get a diagnostic test done on my car?

Engine malfunction warning light control in car dashboard

Most often, a car diagnostic test is carried out when the check engine light on your dashboard comes on, or any other warning light.

You can ask for diagnostic testing on your vehicle whenever you take it to a garage if you feel your car needs it, for example, if you notice issues with your car’s performance or, perhaps if you’ve just bought a new used car or want to keep on top of your car maintenance.

What can a diagnostic test on a car tell you?

A typical diagnostic test from your car’s computer system can identify issues, wear and tear and faults with the following components of your car:

  • Engine and related components including the ignition coils, fuel injectors and air intake system.
  • TPMS (Tyre pressure monitoring system)
  • ABS (anti-locking brake system)
  • Exhaust system (including any contamination and emissions)
  • Transmission and responsiveness
  • AdBlue
  • Lights
  • Comfort controls

A man holding a car diagnostic screen

The diagnostic scanner used for a diagnostic test works by communicating with major components and electronic control modules such as the engine control unit (ECU), also known as the ‘brain’ of the vehicle. The software will show a warning light if any malfunction is detected and give a fault code. The fault codes are used to point the mechanic in the right direction. Allowing them to create a test plan with the aid of specialist tooling to pinpoint the exact fault.

Can I carry out a diagnostic test myself?

Engine diagnostics on a car

Due to the use of specific devices and the need for interpretation by an expert, it is definitely best left to a professional car mechanic. But, with the correct equipment and knowledge, it is possible to carry out diagnostic testing yourself.

Most car owners think that diagnostics can only be carried out by car dealerships but we have state of the art, dealership-level car diagnostics at Peverell Garage that we use to provide a rapid assessment of a vehicle. This applies to BMW, MINI, Volkswagen, Audi, Seat, Skoda (VAG Group) and Citroen, Peugeot, DS group vehicles.

If you do already have any error codes or fault codes from running diagnostics then pass them on to us when you bring your car in so that we can confirm them, before working to fix them.

Why come to Peverell Garage for your car diagnostics?

At Peverell Garage we will always keep you informed every step of the way and never carry out any work on your car before speaking to you about the issues we have found. This means you can have complete peace of mind that there will be no hidden costs when you collect your car from us.

We also have highly trained mechanics, including trained hybrid and electric vehicle technicians and the ability and expertise to put most things right, be it minor faults or major issues. Contact us to see what diagnostic tests and other services we can offer you.

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