Vehicle diagnostics is a highly skilled, involved, technical service. It involves an able technician, time and usually requires expensive diagnostic equipment.

Diagnostics can make some customers a little dubious as unfortunately, within some garages worldwide, misdiagnoses are made. This is most likely due to a lack of expertise or not having invested in the correct equipment. This is therefore a reputation that many, many garages have to counter and disprove and once a garage has established a good reputation in diagnostics it goes a long way.

At The Marlow Garage we specialise in the VAG range and have the latest up to date diagnostic equipment for this range of vehicles. We enjoy a good local reputation for our diagnostic skills amongst other garages, customers and local breakdown companies and often have jobs referred to us that others have been unable to be sort out. Our technicians are enthusiastic and experienced in diagnostics.

As part of our service, we will discuss with you the symptoms the vehicle is experiencing. We will examine the vehicle manually (with some faults this may be all that is required) and sometimes this may require a road test to replicate a noise or a fault that is occurring. If an engine light appears on the dashboard we will also use our diagnostic machine to assist in locating the issue. From the results we carry out tests on components to pin point the exact fault.

A common misconception is that the diagnostic machine does the work but in fact this does not actually conclude the issue. It is simply a really useful tool that a highly skilled, experienced technician uses to accurately diagnose a problem with a vehicle. For example, an engine management light appears and the customer complains of poor performance and the fault code says random multiple misfire and O2 sensor too rich. This would appear that there are multiple issues occurring when actually the O2 sensor may only be ‘too rich’ due to the misfire.

Another example could be a malfunction with the throttle body. This could result in the throttle body being replaced unnecessarily when in fact it could be just broken wires to the throttle body.

Occasionally some issues may be more involved (usually electrical) and in these instances further examination time would be required. Before that is undertaken you would be informed and authorisation granted.

For each diagnostic we carry out a report of the faults found and provide an estimate for the repair. Good advice will also be given with realistic time scales for completion of the repair.

Due to the complexity of the work involved in diagnostics, we always need to carry out our own diagnostics for any vehicle we are repairing to confirm that the correct fault has been found. Failing to do this could inevitably lead to incorrect repairs being carried out.

Our diagnostic service is £59 inc VAT.