Aftermarket March 2022

BY Frank Massey I thought I would begin the new season focusing on how the process of diagnostics works, rather than the fault in hand. To help illustrate this, I am going to add a little humour by comparing it to using sat nav when undertaking a journey. The reality is very similar. Wherein, you often end up undertaking a course of action without all the facts and too much reliance on the presented data. Questions First question: Is the journey strictly necessary at this time? Mistakes often start here, driven by pride and a stubborn determination to fix all faults. We are not here to prove our knowledge to all comers; We are here to offer a professional and profitable service. Faults not worth repairing fall into several categories: A: Cost over residual vehicle value, which strictly speaking, is not our decision. However, I for one have found myself in the position of having successfully completing an agreed repair facing an ungrateful owner with the sobering reality of paying the bill. 28 AFTERMARKET MARCH 2022 TECHNICAL www.aftermarketonline.net PART ONE PROCESS NOT PROBLEM With the first blossoms of the spring almost upon us, Frank thinks a fresh look at the importance of diagnostic approach is in order B: A realistic success ratio. You are thinking of starting a journey without considering all the possible failure points; Where are you going? What is the time of day? Is there the potential for traffic disruption? How long will it take? Intermittent faults may be so erratic in nature that there may not be enough opportunity to observe critical data to establish cause. Never forget the first rule of diagnostics; Fix the cause, do not chase the symptoms. Do you have sufficient uninterrupted time to apply? Will a badly scheduled workload disrupt your concentration? C: Choosing your route. Typing the destination into sat nav is fraught with all the same potential errors of simply following scan tool messages. Firstly, the software assumes many decisions without the benefit of actual knowledge. So, what do we really need before setting off in our leap of faith? Put simply, we must possess more knowledge of our route than the tools on which we rely. My sat nav offers three route options, and I have to choose the one which presents the best chance of success. In order to determine this, I have to have