Vehicle Diagnostics Test

What is a Car Diagnostics Test and How Much Does it Cost?

Regular diagnostic tests can detect problems with your vehicle before they require expensive repairs. Pantech Auto Technicians offer Guildford car diagnostics tests to those driving in and around Surrey.

What is a Car Diagnostics Test?

A car diagnostics test involves using special software to highlight developing faults and issues that are causing problems to your vehicle’s engine or elsewhere systems. This can be detected due to built-in processors, microchips, and sensors.


What happens during a Car Diagnostics Test?

The test will report on the engine, transmission, ignition coils, exhaust, oil tank, fuel injectors, throttle, coolants, airflow and other systems.

The diagnostics check will not include the cost of repairs, replacement parts or recoding. If the garage is unable to offer a suitable repair, they will provide you with the fault codes that will enable you to obtain repair quotes from specialists.

A full test can take between an hour and 90 minutes to complete. If issues are uncovered that make things more complicated, or components need to be removed for the test to be performed, the time can increase. This does not include the time required to fix any of the issues or problems discovered.

Car Diagnostics Test


How much does a Car Diagnostics Test cost?

The cost of a car diagnostics test will vary depending on where in the UK you are getting it done, and if it is a garage or other type of establishment. The car model can also affect the price, as some models may need more sophisticated equipment to carry out the test. Luxury cars, unique vehicles and sports models may also cost more due to it taking more time to test. The standard cost is between £50-£100.

It is recommended to have a car diagnostic test regularly to prevent severe problems from occurring, as you can detect the minor issues and fix them before it becomes a major problem, requiring hundreds or thousands of pounds to repair. This makes it a more cost-effective approach than taking your vehicle to the mechanic when it has broken down.


What are Diagnostic Trouble Codes?

Most diagnostic codes have been standardised and are known as “OBD-II” (on-board-diagnostics). These codes are triggered when a fault is detected or a system is not working as it should be. The code is stored in the vehicle’s memory and can be accessed in a diagnostics test with specialised software.

There are over 200 fault codes that may be generated, but they fall into the four main areas:

  • Body codes, prefixed with a B. This covers things inside the passenger compartment, such as airbags, air conditioning, passenger comfort and safety, and driver assistance.
  • Chassis codes, prefixed with a C. This refers to most of the mechanical systems, including suspension, braking and steering.
  • Powertrain codes, prefixed with a P. This refers to the engine components, transmission and drivetrain parts.
  • Vehicle network codes, prefixed with a U. This includes the wiring and other vehicle integration systems such as the computers and sensors.


If you would like to book your vehicle a diagnostics test, please contact us at Pantech Auto Technicians today for more information and a no-obligation quote.