Helping a customer to trouble shoot a VQ swapped Spec V.. I've never had a ECU go bad, but I think that's what we've narrowed it down to.

Here's the symptoms and what we've tested:

Car died suddenly at highway speed (was raining heavily)
No spark at all
Can smell fuel while cranking
Fuel pump primes
ECCS relay is working:
- power at coils, injectors, MAF, crank and cam sensors
All fuses check out
No codes
Replaced crank sensor with new one from Nissan

The fact that he is getting 12 volts switched to all of the sensors, tells me that it's not the ECCS relay. The fact that the pump primes, and he smells fuel while cranking tells me that the injectors are working. No spark with good voltage and ground means that it pretty much has to be the ECU. Anyone else ever have a ECU go bad?

Travis

 

i've had to replace very few ecu's on the 2002-2003, and those that needed to be replaced were due to external damage and not what you are describing. Sounds to me like electrical fault. I've had experiences where connection in the connectors gave out in heavy down pours or puddles. Did you trouble shoot your wiring?

 

What about Nats ?
VQ35 ecu rarely goes bad. However on the 350z/g35 there were times where the ecu got damage from.water due to a bad seal on the harness on the firewall.

 

I replaced my ecu recently because I could not connect to my laptop software. I kept getting an error message that the ecu was in an incorrect state. I was unable to advance or retard my timing or read codes. 2 months before this happened my TPS died. I think rhis caused my problems. I even took the car ro a dealerahip to get the idle air relearn done and they could not get it to work. Swapped the ecu and now I can communicate with it again

 

I had something simliar happen to me. I had a UTEC installed that ended up going bad and it was uninstalled. Somehow there was a loose wire on the ECU. Driving along in the rain and the car just died. I also had a really bad misfire happen at the same time. Not sure if this is the same issue you are having though.

 

I also thought about NATS but the OP said the car died on the freeway therefore I eliminated from possibility.

 

Yeah, NATS would have to be no-start fault, and would throw a code. In other words, it wouldn't just die going down the highway because of NATS.

I haven't looked at any other wiring (car is not here), but if everything else is working, and there's no codes, I don't think it's wiring. There's only so many things that can cause no spark. We have power to the coils, but no fire, and the injectors are firing. So, that eliminates pretty much everything except the ECU.

 

the only issue i had recently on my max (2002 6spd 59k) that my ecu wont send out voltage to the evap solenoid so the evap system will do its thing so i always have a code po444 which is so anoying...either take the ecu out and try to find a way to fix it or buy another one

 

If the ECU went bad on the 5.5 Gen max could you replace it with the 350z ECU? they both have 116 PIN. I was looking at the FSM and I know that all of the 350z piggyback Engine management units; UTEC, Haltech, etc can be wired to work in the 5.5Gen Max. Going 350z ECU you can just PnP any aftermarket ECM in there. Just asking.....