I have a 2000 Maxima MT (federal).

I have been on my 4th IACV for about the last year and a half. All had been fine, and then, boom, another bad IACV. Took it to the shop and the IACV won't respond to the tech computer. The first 3 had been NAPA parts, but after other forum suggestions I had my ECM checked out at Nissan (which they said was fine, but who known cause that dealership stinks) and I replaced the IACV with a genuine Nissan one. Again, everything had been fine for about a year and a half.

I am at my wit's end on this, so I'm at a loss as to what to do.

Should I send my ECM off to get it repaired even though it has been declared OK? I still think that might be a good idea and I could send it to the guys in Van Nuys (I think it is) and have pretty quick turnaround. Could the ECM be sending the spike that is frying the IACV? I could then get another IACV and TPS and all should be good with the remanufactured ECM. I only have 75K on the maxima and I was hoping it would last me a long time as it's the first car I bought and I have a van that goes long drives. I hate to keep throwing money away, but buying a car is also an expensive proposition.

 

Well here's the thing, it's thought that the IACV is not damaged by the ECU, but by coolant shorting windings in the coils. That in turn can fry the ECU since it attempts to drive a short. I don't know anyone who has had the reverse, an ECU just go bad and spike an IACV to death. In fact that would surprise me, the coils in the IACV should be able to handle voltage spikes, it's just a wire. I also doubt the mosfet driver can put out enough current to overheat those windings. Anyway, I'd ohm the IACV coils, I wouldn't trust a shop saying they can't control it. You can also inspect your ECU, look to see if the mosfet is blown or has a chipout, any signs of stress.