October 2021

T o carry out electrical and diagnostic repairs on vehicles, technical information is a must. With modern vehicles now having so much wiring and sensors, trying to fix for example a wiring fault without knowing what each wire is, what it does and where it goes in my own personal opinion is ludicrous. In this article I intend to show the importance of having not only technical information to hand but the correct information. Assessment Recently, a customer telephoned looking for some advice regarding her vehicle and whether it was safe to drive. The customer explained that she had a 2010 Ford Mondeo and that the engine management light had came on while driving along the road. On the plus side, the car drove fine. We explained how without seeing the car it was hard to comment and recommended the vehicle be booked in. The next day the customer phoned to say the vehicle had broken down and had now become a non-start. She wondered what her options were so I explained in my opinion, the best route to take would be to get the vehicle recovered to allow me to carry out a diagnostic assessment of her vehicle including a thorough test plan which included referring to wiring diagrams and technical 34 AFTERMARKET OCTOBER 2021 TECHNICAL www.aftermarketonline.net INFORMATION OVERLOAD Sometimes too much is never enough, but according to Neil, you can never have enough information on a repair information. This would allow me to come to the correct conclusion of what was wrong with the vehicle. We agreed to an initial assessment and I would then notify the customer what I had found with potentially even a fixed vehicle. A few days later the vehicle was recovered to our workshop and another call was made to the customer to notify her that the vehicle had arrived and to ask some more questions about the faults. The customer complaint was that while driving along the road the engine management light had illuminated but the vehicle drove fine with no loss of power or any other notable symptoms other than a warning light on the dashboard, however the following day while driving along the road and hitting a bump the car cut out and now when turning the key to the crank position nothing happened. After pushing the vehicle into the workshop, I firstly confirmed the customer complaint. As stated, there was nothing when the key was turned to the start position, however with the ignition on all lights illuminated as they should except the engine management light, if you read my last article (which I am hoping you have) you will know this is a big clue. After attempting to do a global scan with Ford IDS, it reported back many fault codes for no communication with the powertrain control unit (PCM), BY Neil Currie