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Diagnostic game-changers

Autotechnician readers share their thoughts on what tools and techniques have changed their approach to diagnostic investigation

To excel at a task, it is not enough to have the right tools for the job, but to know how to use them to their full potential and how to apply them efficiently to the specific task in hand. As vehicles continue to break away from a simpler, mechanical powerhouse they once were into a finely tuned system of communicating microchips, is it possible to know every system, from every manufacturer, inside out? There are many fine master technicians out there who tackle this complicated tech and do their homework at every opportunity; sharing ideas on forums, training regularly, following case studies in magazines and logging the more awkward jobs that come through their doors in order to develop ever-more sophisticated repair techniques. And after speaking to hundreds of technicians over the years, from apprentices who are starting out in their career to the best repairers in the UK – succeeding in attaining that first-time fix is, like every challenge in life, all about having the right attitude.

We asked a number of technicians, including two chaps who have moved from the garage floor into diagnostic tool development roles, what they considered to be the tools, techniques or bits of training they have picked up along their journey which they consider game-changing in their approach to diagnostic work, in the hope that some nuggets of information may strike a chord with you dear reader, and serve as inspiration to keep striving for that perfect, first-time fix.

Martyn Langbridge, Cheltenham & Gloucester Autocentre in Cheltenham
Martyn believes that it’s the preparations that enable correct diagnosis rather than the art itself…

“Having the right attitude to running your workshop and diagnosing faults is key. The best places to network and meet people who can inspire you – such as Frank Massey, James Dillon and Andy Savva – are events and exhibitions. These trainers give you the correct attitude that attending courses isn’t a burden, cost or waste of time, but vital. I have had some excellent training from James (Dillon of Technical Topics) that has progressed our business.

“There are so many tools that help us diagnose and I wouldn’t be without any of them, but for me it’s all about everything except actually doing the job – staff, attitude, training, tooling, image, parking, reception… all come before diagnosing or repairing a vehicle.”


Andrew West of Erme Valley Autos in Ivybridge, Devon

pico“There are a couple of things that I consider a bit of a ‘game changer’. The main one was the Pico WPS500X pressure transducer, which opened up a whole new aspect of diagnosis, enabling examination of cylinder compression and valve events, amongst many other uses.

“My eyes were opened when I met Jean and Frank Massey, who showed me that these hidden signals were present in automotive electrics and they could be viewed with an oscilloscope, which I was completely oblivious to at the time.

“I attended a training event with Mark Carter, who explained (what now appears simple) how to calculate the theoretical air mass entering an engine. This has greatly helped with the diagnosis of air mass meters & EGR valve operation.”


Matthew Pestridge of D&D Autos in Ashford, Kent

Pestridge“I have been doing diagnostics for quite a few years now and one of the key things I have learnt is the importance of having a methodical approach. When a vehicle comes in, I will have an action plan so that I know what I am doing and where I am heading. This may sound simple, but I have seen many people start to diagnose a job only to get lost in their own thought processes. The consequence of this is a loss of time and possible misdiagnosis.

“I have attended several training courses over the years, the majority with Bosch and several with independent training providers, such as Frank Massey, ranging from basic electrics, hybrid vehicles to diesel systems – all have been extremely beneficial in how I diagnose a vehicle. Training has always been a priority for me and is an ongoing activity; I am always looking for new training avenues that will broaden my horizon. It’s a means to keeping abreast of new technology, especially as the modern vehicle gets more complex!  It’s also a great forum for sharing ideas with fellow colleagues in the industry.

“Diagnostic equipment has changed a lot over the years. There was the Crypton Act that was purchased back in the 90’s and a VAG 1552 (I still have both in a box in my office) to now using pass- thru and dealing with the manufacturers direct to do the more special functions. As an independent garage working on all makes, having one piece of equipment that caters for every manufacturer and getting the repair data has been challenging, however, I have made some significant investments in various pieces of equipment over the years, which have helped me keep abreast of new technology. Despite this investment, diagnosing all makes is difficult, especially when it comes to coding and programming the parts once they have been diagnosed. Even just checking for the latest software can be a headache, however, this is where having the knowledge of using the manufacturers’ websites comes in extremely handy!”


Anthony Pickering of CBF Service Centre in Suffolk

“It is hard to pick one specific ‘game changer’ that has made my diagnosis life easier. It’s a combination of training (live and online), using good tooling (oscilloscope, electric test meters, smoke generator, pressure/vacuum gauges) and combining the two, together with lots of practice of different testing techniques to hone a fault-finding technique which has reliable results.

“I still learn something new every day.”


Mark Banks, Diagnostic Development Engineer at Robert Bosch

mark“For me, the tool that changed my outlook to vehicle diagnostics was a good quality digital multimeter. The moment that the ‘Diagnostic Penny’ really dropped for me, about 20 years ago, was learning about, and understanding the principle of, ‘volt drop’ in electrical circuits.

“In an automotive world of ever-advancing technology, it is so easy to over complicate a job by missing the basic initial tests when looking for an electrical fault on a vehicle. The benefit of volt-drop testing is that you are examining the electrical circuit in its operating state, which is the best way to spot a problem. Bosch Automotive run an excellent training course called VSE1 – Essential test procedures, which covers this topic and is often an ‘eye opener’ for many technicians that attend.”


Lee Pritchard of Bowydd Garage in Gwynedd

“When doing day-to-day jobs and from a diagnostic point of view, the tool I couldn’t do without is the ‘Smoke machine’. I was introduced to it a few years ago on a Diesel training course by Technical Topics. The smoke machine is an excellent tool for flushing out such faults as Sticking EGR valves, intake leaks and vacuum pipe leaks, where access is very limited.

smoke“A few recent jobs we had in with a sticking EGR was the 1.6 VAG diesel engine, where the EGR is at the back of the engine. It’s very awkward to access, but with the smoke machine, no dismantling was required to diagnose. The smoke machine has become one of the first steps in the diagnostic process in our garage. Thinking back to when I was trying to diagnose faults before using this, I recall how much time and effort I was wasting – now I can do an evaluation of the complete intake system in under 10 minutes, making it a big time saver. We still hear of a lot of local dealerships are still not using this tool.”



Ainsley McEwan, semi-retired from McEwan’s Garage in Derby

“It’s difficult to pick one item because each piece of equipment, or training over the years, seemed to interlink, but I think one of the most important for me, was back in the mid 1990’s when I bought a digital oscilloscope.

“I had used CRT scopes with engine tuners but the digital scope, with the ability to display multiple channels and freeze/save the images, really helped me to start understanding sensor operation and their relationships. The digital oscilloscope gave me the confidence and knowledge to diagnose faults others couldn’t and the fact I had four at one time says it all.”


Andy Gravel, ADG Autotech in Scunthorpe

gravel“I was first introduced to the WPS500X Pressure Transducer at James Dillon’s Diagnostic boot camp and returned home inspired, and had one on order within days. With the PicoScope already being an everyday essential tool, the WPS500X makes an impressive addition. I was initially shown its use for in-cylinder compression testing and it quickly became apparent that its uses are endless.

“To be able to test and record pressure over time with the level of detail and accuracy available with this tool, makes testing the likes of an intermittent fuel pressure issue a one-man job. The data can be analysed, saved and shared with colleagues or customers, supporting the value of the diagnostic process.

“I most recently used this to test and record an engine oil pressure issue after a turbo failure. The vehicle was displaying a lack of power; the oil pressure was tested and was found to be low, causing the turbo failure. The customer failed to mention the oil pressure light remained on for an excessive amount of time after start-up, he was told by the dealership that this was nothing to worry about and probably a switch issue, so the customer took a little convincing that it was an oil pressure issue. Having the data recorded and printed to display to the customer as evidence made my job easier.”


Steve Smith, previously a master tech at a Toyota dealership, now Automotive Application Specialist at Pico Technology

volts“A game changer for me was learning Ohm’s Law and voltage drop, and applying them in the real world. This might sound very ‘theoretical’ but it really is where theory meets practice. I knew I had to understand these electrical principles in order to provide what I saw at the time as job security – given my colleagues were happy with routine work and avoiding electrical work like the plague!

“Having firm electrical foundation knowledge that I could apply in the real-world during my YTS (that’s the Youth Training Scheme to our younger readers! Ed) soon brought all kinds of work outside of the norm. By no means did I fully understand what I was working with but once again, understanding the principles and theory got me through and has paid dividends. The training I received during ‘day release’ to college back in 1984 to 1988 – I still keep in touch with my electrical lecturer today. I owe him big time.

“The best tool would be the one I invested heavily in back in the 80’s and still have today. I paid around £270 with the interest, which is a lot when you earn £25 per week! It was the simple Multimeter made by a competitor that I cannot mention, but their name begins with ‘F’ and ends in ‘E’ with ‘LUK’ in the middle. Great tool, great quality, lasts forever.”


Kim Doerr, K D Auto Services in Bedford

kim“In the early days of my diagnostic experience we had Sun and Crypton machines, they kicked off my interest in fixing the actual fault and not just guessing. The live oscilloscope on these machines was always the most interesting part and has evolved into what I have to say is the biggest game changer of all.

“To actually see what is going on in a circuit is vital on modern vehicle systems and I couldn’t do half of my work without it.

jukebox“For me, the PicoScope is the best tool I have and I had an unusual job for it recently. My 1957 Jukebox was playing up, not selecting correctly, the amps clamp on the PicoScope showed a much shorter millisecond duration on some of the selections. It turned out to be a very slight mechanical adjustment of a solenoid. If it had an ECU I’m sure some people would be throwing a new ECU at it!

“I have bought some diagnostic scan tools just to stay up to date and they have cost me dearly, but if I hadn’t, I’d have been left behind many years ago… Life is one great big learning curve.

“I’ve used VCDS for many years – and has paid for itself many times over. I have many other scan tools because not one will do everything. I use Smoke Pro a fair bit too, this is one of those tools that never gets outdated and has earned it’s keep – simple and effective!”

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Autotechnician is a magazine published nine times a year, delivering essential information to independent garage owners and technicians in the UK. Delivered both digitally and in print, autotechnician provides readers with technical, training, business advice, product and news, allowing our readers to keep up to date with information they need to run and work within a modern workshop.
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