what's up guys i need help. So i bought a 2006 m/t rev up g35 coupe that had a rod knock and i swapped the engine to a 2003-04 de with roughly 50k miles, i bought a new ecu and did a whole rebuild and then when it was time to turn on the car it connected and i found out that the car was overvolting and under volting, the ecu is fried now because there is a short and i am desperately trying to find it, i will give the person that gives me information that helps my car turn on $500. i will be posting updates when i have them but i am desperate so any information helps thank you.

 

So the ECM is probably fine, I've seen them run at 18v before without any issue (racecar stuff it's becoming more common to use a separate 18v Milwaukee battery for your ECM and a separate battery just for start/ignition).

Are you sure it didn't just blow something in the fusible link or the IPDM. That's a lot more likely than actually screwing up the ECM.

Under voltage the car is just going to weak spark and shut off eventually. How did you determine that the car was actually over voltage though?

You can always start/run the car with the accessory belt disconnected to get the vehicle running initially, you won't have alternator charging or power steering, the water pump is driven off the timing chain.

As for the short, if there IS a shorted circuit it's going to blow a fuse, I'd start there. Check the fusible link, the IPDM, and the cabin Fuse Block - J/B.

If you don't already have a copy of the factory service manual you can download the entire thing for your car from Nicoclub, no account needed. I recommend downloading the 2006 coupe and the 2004 coupe since you have switched to a completely different engine by putting the non-revup engine into the car that came with the revup.

Did you keep the existing rev-up ECM ? I think that's the one you'll need to get the car working since there were some changes on the wiring harness with the non-revup ECM.

 

Also check out these threads the most recent person to do a rev-up to non-rev engine swap was Raygun. He used a 350Z ECM

https://g35driver.com/forums/engine-...start-yay.html

This one the same user was getting the BCM/ECM pairing figured out with Nissan Datascan 2

https://g35driver.com/forums/g35-cou...ol-nats-2.html

 

Ohh and here's a link to the FSM

https://www.nicoclub.com/infiniti-se...ls#g35_g37_q40

You mostly need section PG - Power/Grounding to trace circuits on the fusible link, IPDM, and Fuse Block - J/B. Section EC - Engine Controls under the section "trouble diagnosis" you'll find the ECM pinout / harness terminal connector layout. Make sure you have the right harness for the right ECM.