I originally did a full automatic-to-manual transmission swap on my 2003 Infiniti G35 sedan. After completing the mechanical part, I did the jumper for the Park signal so the car would start, and everything worked fine — I started the car a few times, revved it, no issues.

Later that day, I had a friend over who owns the UpRev Tuner version. He usually tunes Mopars, Chevys, etc., using HP Tuners and bench flashing. We didn't know at the time that UpRev doesn’t support the 2003 G35 sedan ECU. So he proceeded to do a ROM dump and sent it to UpRev hoping they could provide a base map.

Right after the ROM dump was completed, the car wouldn’t start anymore — and it hasn’t started since. It's been about 3 weeks to a month now.

I’ve tested all the fuses inside and in the engine bay. I haven’t tested the relays yet. From what I’ve seen, when an ECU is fried, the radiator fans usually kick on right away — but in my case, the fans are behaving normally.

I even swapped in a different ECU and had a locksmith program my key to it, but still no start. The engine cranks, but won’t fire.

Before replacing the ECU, I was getting codes like P1122, P0605, and later U1000. After swapping the ECU, I only checked if there was communication — and now, no communication at all, just like with the original ECU.