Automotive Diagnostics

Advanced Fault Finding at South Wales' leading BMW & Mini Diagnostic Centre

Identifying the Problem

In order to diagnose a fault, we need to establish exactly what problem you want resolved.

Investigating the Problem

Once the fault is identified, we need to investigate the potential causes and establish why its happening.

Resolving the Problem

Once we know the cause and any consequential issues, we can price up the repairs to resolve the problem.

"Calling a code scan a diagnostic is like calling a slice of bread a sandwich"

The difference between a code scan &
a diagnosis

A code scan provides details of the symptoms of the fault, which are not necessarily the cause.

Put simply a code scan will access the vehicles stored DTC (diagnostic trouble code) error log and report back with any P Codes (fault code identities) found.
The fault codes are triggered when data from one or more sensors does not fall within the programmed expected values. Some fault codes are programmed to cause a warning light or error message and some are programmed to cause a restriction of performance to prevent further damage (often referred to as "limp mode"). The sensors on modern vehicles monitor all sorts of aspects of the cars functions and a out of specification sensor reading could in fact be a blip or simply an accurate report of the status of a component.
For example if a fault code is logged for the MAF (mass air flow) sensor, is it because the sensor has failed or is it because there is a small air leak causing the airflow readings to be out of expected tolerance ranges? If you decide a repair based on the code scan you might needlessly replace the MAF sensor and still find you have an EML (engine management light) after the "repair".
Then you'd have to start all over again.

Hence our assertion that a code scan simply is not a diagnosis.

The diagnosis may start with a code scan to give an indication of what system needs looking at, but unless you like throwing parts at your car to try a fix, we suggest that you let an expert do further investigations and proper interpretation of the DTC error log.

As a specialist diagnostic centre, we feel we're the best choice for the job and if you give us a chance we're confident you will too!

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The Importance of Tooling

It's not what you use but how you use it does not apply to diagnostic equipment!

Obviously how you use it is important and we only allow our experienced, qualified, fully trained technicians to carry out diagnosis for us but the point is that the quality of the tooling used is also an important factor for the accuracy of the data obtained.

Using a cheaper generic code reader will provide some information but probably not very meaningful information for narrowing down a fault. The manufacturer approved equipment is designed to communicate with all the modules and systems in the vehicle and can provide a much greater depth of information on any codes logged and data obtained.

Some of the aftermarket tooling is brilliant for certain tests and works so we've ended up with the best of both worlds and a wide array of both manufacturer tooling and the best of the aftermarket to maximise our capabilities.

Code reading, manufacturer guided test plans, live data assessment, actuation tests, emissions analysis, dynamometer analysis, leak detection, coding functions, ecu testing, you name it we can probably do it!

"It's not always about finding what's wrong, sometimes it's easier to prove what's right"

Proper Fault Finding

No Guesswork, Just Accurate Diagnosis

Advanced diagnostics is about identifying the problems with your car accurately. We use a multitude of in depth procedures to test the cars systems for variences from the programmed expected values.

After the initial code scan gives us an idea of what sort of faults are occuring, our diagnostic team can formulate a test plan to find out exactly where the problem lies. We might start with a leak test or oscilloscope monitoring, we have all the equipment and experience needed to find any fault.

Value For Money

It's nice to know what you're paying for

Qualified Staff:
Lots of mechanics are QBEs (Qualified By Experience) which effectively means that they have had no formal teaching or exams to pass. Whilst this may have been fine with old school cars, modern cars are very technologically advanced and need working on by a specialist. All our technicians are qualified with certification to prove it!

Cutting Costs:
Our workshop cuts costs, not corners! We may not have a big flashy showroom or marble floors but we do have a smart clean workshop. Thanks to our cost saving efforts we can keep our labour rate much lower than the dealerships with huge overheads.

Time Is Money:
Unfortunately the old adage is true, time costs money. For every hour we work on your car we are paying staff wages, electricity, building costs etc. It adds up and we have to cover those costs by billing for what we do. Please don't ask for freebies, we hate saying no but we have to.

Estimated Costs:
We offer different packages to suit (see below) for fixed pricing. Beyond these, all diagnosis is done on an hourly charge basis. Remember you're paying for qualified experienced staff, not cheap low paid grease monkeys. This is also less than half the price of the BMW dealership hourly rate.

At DIAGNOSTICS.WALES we follow a set five stage process that we know works

It starts with Communication

We will ask you to complete a brief questionnaire to provide some background to the fault(s) you want investigated and the history of the car.

This is tedious but more important than you think as we use this as the basis for what we are aiming to resolve. If you don't tell us about it we won't be looking for it.

Some problems are intermittant or subjective such as a noise or smell. In these cases the diagnostic technician needs as much information as possible, to find a fault it really helps to experience it. The technician may request to go on test drive with you or ask you some extra questions so please prepare to spend up to 15 minutes at the workshop when dropping a car off for diagnostics.


Initial Assessment

The first stage of any fault finding is a code scan (this is not a diagnosis but it's a good starting point) to establish whether there are any fault codes logged on the vehicles DTC (diagnostic trouble code) error log.

If you've opted for just the Basic Code Scan, our assistance ends here. We'll give you a printout of the results but no interpretation or further analysis is included in the basic code scan pricing.

Our Initial Assessment package includes up to an hours worth of diagnostic technician labour to analyse the dtc history, carry out the basic test plan and commence further investigations. At the end of this process we will have a good idea of either what needs to be done to resolve the fault or what further testing (advanced diagnostics) is needed along with the costs involved.


Advanced Diagnostics

If further investigations are needed its usually to ascertain for definate whether a component needs replacing or if its actually a wiring or control module issue. We guarantee not to replace a part unless we have proven that it is necessary. Our motto is simple, if it isn't broke don't fix it!

Sometimes a problem is very complex or happens so intermittantly that it is difficult to diagnose, these faults can take longer to identify but we've never been beaten yet provided the customer is patient and allows us the time to follow the processes. In these instances it's often more about proving what is working correctly as a process of elimination.

We record every step of the diagnosis on your car with a detailed diagnostic log which forms part of the report you receive from us.


Recommended Repairs

When you receive our report there will be a conclusion with details of any recommended repairs. There may be more than one fault that's been identified and in these cases the repairs will be ordered by priority based on safety and functionality.

Your customer service advisor will get in touch with estimates for the recommended repairs and we will always contact you with prices for any parts required prior to fitment.

Sometimes repairs end up being completed as part of the diagnostic labour (ie. if a broken wire is found, we would repair it in the process).

Labour time spent on your vehicle is chargeable and with advanced diagnostics you should be prepared for the potential of minor amounts of additional unexpected labour.



Customer satisfaction is very important to us. We want you to be happy with the service and results of your visit. We try to keep you in the loop at all times and we work hard at explaining things clearly without jargon or technobabble.

We are always eager to receive your feedback and would be delighted if you can spare the time to fill in one of our surveys in reception.


"Our Customers are pleasantly surprised at our pricing structure"

Basic Code Scan

  • BMW Code Scan / Mini Code Scan
  • Dealer Level or Equivalent Tool
  • Error Log Printout
  • NO TechTime or Intrepretation

Diagnostic Initial Assessment

Our Most Popular Package
  • Dealer Level Code Scan
  • Up to 1hr Technician Time
  • Initial Checks & Testing
  • Written Report & Conclusion

Advanced Diagnostics

  • Competitive Hourly Labour Rate
  • Qualified BMW Trained Technicians
  • BMW Focused Experienced Expertise
  • Guided Testing & Accurate Fault Finding

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