I’m fairly handy on a car, but electrical work is well beyond my qualifications. Tried to start my '01 Nissan Maxima, and it wouldn’t turn over despite everything sounding good and seemingly working. Took it to a shop I’ve worked with plenty over the years (and used to trust a lot), and this is the story they are painting:
The rear engine mount is busted (which after looking at it I buy) caused the sensor to fire, which some how cause the ECU to get fried. I want to note they took a full 3 days to come to this diagnosis. I’m buying the rear engine mount problem, but my research into the sensor indicates that the blown sensor shouldn’t prevent it from turning over. I’m concerned that some how the ECU was damaged in another way (not necessarily by the shop or maliciously).
It’s got 144k mi on it, and the only symptom of electrical problems I can think of is that we have a key that only starts the car 80% of the time (and 1 key which previously always starts it). I understand that the key is supposed to send a coded signal based on the VIN to the ECU to get the car to crank, but I’m not sure where along that line it would cause ECU failure.
Am I way off to think this sounds like a stretch?