MAY 2023 AFTERMARKET 25 exhausted all limited direction of diagnostic enquiries, it was time to put the train back on the tracks. Please refer to Fig.2. I consulted a local friend and expert, Paul Emmett from Fig. 1 Reedley Service Centre. This was correct decision number one. He owns the Ford IDS platform, with which one can programme and code the PCM. Following this process, the keys operated the central locking, and the instrument cluster became active. Despite this apparent progress, there was still no cranking. As part of the coding process though, a global scan was conducted, resulting in a curious and previously unknown error. It turned out that both rear wheel speed sensors were defective. Paul suggested replacing them before continuing; Correct decision number two. The sensors were replaced, and the vehicle started normally with all stored codes cleared. I place this explanation in the same column as my previous observations. In short, wheel speed sensor errors are broadcast on high speed CAN, therefore the error frames must have corrupted the network, thus preventing crank start. The failure to understand this I put down to incomplete serial data from TOPDON. I am sure I don’t need to recap events, and I am not going to expose the decision makers, but as the technician in question I should have refused to continue. This was mistake number five. I don’t know what the owner was charged for the repair, but I hope it was more than the original estimate. Challenges Let’s end on a little restored personal pride; A Ford Transit Connect with a faulty power steering assist system was presented, with a blown 60amp control fuse for good measure. Challenge number one; Ford would only supply a complete vehicle wiring harness for £600 despite the auxiliary fuse panel being easily replaceable. Please refer to Fig.3. I decided to replace the fixed fuse assembly with the correctly rated value and conduct current flow analysis by logging serial data and directly using my personal fluke clamp. Current peaked at 65amp for a few milliseconds. Average current flow was 35amps. Please refer to Fig.4. I was made aware of known issues with steering rack faults, and I am waiting to see if the fault reoccurs, which will mean a new rack assembly is required. This customer has no issues with cost. I have archived many examples of good and challenging decisions facing technicians with limited access to essential assets. More next issue. Fig. 2 Fig. 3 Fig. 4
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