Aftermarket December/January 2023

DECEMBER/JANUARY 2023 AFTERMARKET 27 Next issue: A diagnostic case study from Ryan Colley the stall event. If not, I could then determine if injector pulse ceased due to a loss of a cam or crank sensor signal. As you can see from Fig.3, the cam and crank sensor signals remained and the injector control was the first to be lost, thus resulting in a stall of the engine. The engine computer was no longer providing injector control to keep the engine running. Since proper cam position signal remained during the stall it was unlikely to be a 5v reference fault, as the 5v reference is used to power the camshaft sensor. At this point, from the evidence I had retrieved coupled with the fault code I initially found, I was highly suspicious of an internal engine computer fault. There are no problems, only solutions Due to the current issues surrounding the supply of electronic parts in the UK I was not able to obtain an engine control module directly from the dealership. I had only one option which was to locate a used control unit and carry out cloning of the original control module. This process requires removal of the engine computer from the vehicle and connecting a programmer directly to the ECU. Please refer to Fig.4. You are then required to read the flash and the EEPROM internal to the computer and transfer that data from the suspect's faulty original ECU into the donor ECU. Please refer to Fig.5 and Fig.6. By going through this process, you are effectively making an exact copy of the original ECU, allowing all the immobiliser and coding data to be transferred so you can simply connect the ECU back to the vehicle without any further programming being required. This will only rectify a hardware-related fault. If there was a software-related issue, then you will effectively copy the fault onto the donor unit. I was confident this was a hardware-related issue rather than a software-related problem. Once I had cloned the ECU, I left the engine idling to attempt to re- create the original complaint. I can confirm the donor ECU I cloned had fixed this intermittent fault as the stalling no longer occurred. With intermittent faults, the best way to tackle them is to gather as much data as you possibly can, performing as little work as possible. This will then stop the hours and hours of stripping parts off needlessly to carry out inspections that are not required. A solid foundational knowledge of how systems operate on today's complex vehicles also provides a strong advantage. Logic can then be used to narrow down the possibilities that could cause the fault as we have done in this diagnosis and repair. Fig.4 Fig.3 Fig.5 Fig.6 With intermittent faults, the best way to tackle them is to gather as much data as you possibly can, performing as little work as possible ”