July/August 2019

BY John Batten H ave you ever wondered why it is that some technicians have an aptitude for complex diagnosis? You know the type of tech I mean. They take the seemingly unfixable, dive headlong into diagnostic battle and emerge triumphant time and time again. Not only that, but they’ll often do so in a time that makes other techs look on in awe! What’s their secret? And more importantly, can you emulate their success? Well, I’ve got some great news for you. You can, and knowing what to do is easy. All that’s required is that you look to the past. History is a great teacher. I turned 50 this year, and one of the few benefits of increasing age is the ability to spot patterns, and patterns of actions that when followed culminate in your success. Patterns for success surround us, but sometimes you can be a little too caught up in the urgency of the now to spot them. I’ll show you the patterns great technicians use to triumph in the world of technical diagnosis, and how you can do the same. It’ll be your blueprint for success. You’ll like the blueprint. You’ll appreciate its simplicity, recognise the logic, and in all probability nod along as you read, agreeing with the steps that need to be followed. Here’s the deal though: You’ll need to implement it. Knowing the blueprint is easy, but knowing what to do doesn’t get the job done. It’s all in the implementation, and that starts with you taking small steps to achieve positive changes each day. Don’t forget one of my favourite sayings: “Progress NOT perfection.” I’m as much a fan of the latest technical gadget as the next man. I also love “cool” test techniques, but I’ve noticed that myopic focus on these can often be to the detriment of the long-term technical success of a technician. I’m not saying that you shouldn’t explore “shiny” elements in our craft, but you’ll find huge benefits in building a solid foundation that can be executed on every diagnosis. What do you need to “do well” then? Just these five steps. Step one – Systemise to win There’s always a right and not so right way to attack any given fault. One fundamental element is to have a defined system that all technicians use. Without a rigorous system to follow, your diagnosis could be doomed before you start. Here’s an outline of our diagnostic system that just works; 1 – Thorough questioning of customer, establish change point 2 – Confirm and experience fault with customer 3 – Visual inspection for obvious issues 4 – Retreive fault codes, and gather data on what’s required to raise them 5 – Inspect serial data. Note what looks wrong 6 – Research technical bulletins and any technical information required for accurate testing. 7 – Document what’s wrong and possible causes 8 – Form plan and prioritise relevant tests 9 – Carry out tests and draw conclusions 10 – Bypass test to prove the conclusion where applicable 11 – Repair as required. 12 – Carry out postfix operations i.e. component coding. 13 – Carry out tests to confirm repair Use our process and you’ll definitely be putting your best foot forward. Step two – Sound electrical knowledge Now you know what a great process looks like the next part of your blueprint is your understanding of automotive electrics. How quickly you can decide what to test, what tool to use, and what the answer should be is an essential skill that pays huge dividends once learnt. Key elements include: 1 – Becoming comfortable with relationship between volts, amps and ohms 2 – Using voltage drop to accurately find circuit faults 3 – Series and parallel circuit diagnosis 4 – Interpretation and use of wiring diagrams 5 – Fundamental mechantronics test knowledge Armed with these, you’ll be able to find wiring faults, diagnose sensor and actuator circuits as well as build entry-level bypass tests to confirm your theories. These are skills you’ll use on the majority of diagnostic repairs. Learn these and you’ll reap the rewards for your entire career. Step three – Oscilloscopes; One tool to rule them all A little dramatic I know, but understanding how to use an oscilloscope competently is a game changer. It will bring to life all that has been learned in Step two (auto electrics), and when used skilfully will display this in a way that can confirm or deny faults in vehicle circuits, sensors and actuators. As an example, take just one quick connection (less than a minute on most petrol cars) to the switched side of a manifold injector and you’ll know; 1 – That power supply to the injector is not open circuit 2 – The ECU has control of the injector and is commanding fuel delivery 3 – Time taken for fuel delivery to commence (injector opening) 4 – Integrity of injector ground circuit 24 AFTERMARKET JULY/AUGUST 2019 TECHNICAL www.aftermarketonline.net BLUEPRINT FOR TECHNICAL SUCCESS Want to increase your first-time fix rate and reduce your diagnostic stress? John says you just need to follow his Five Step Blueprint