04 pathy 3.5 Eccs1 fuse issue help.

[Tattoobabyy]

So I’ll start from the beginning. July 1st she shut off idling at a light on me. Honestly thought she run out of gas ( gas gauge has never worked ) messed around with it realized she didn’t have an fuel pressure at all second thought was the fuel pump went ( it’s been weak for sometime ) replaced it and she still wouldn’t start. boyfriend got it to start but as soon as you put it in gear it died. I tried to start it the next day it wouldn’t start. Looking at fuses it blow the eccs2 fuse replaced it and it ran the very best. Drove it up to Canadian Tire ( 5minutes away) it shut off at idle sitting in the parking lot. It blew the eccs1 fuse replaced it and it still wouldn’t start. Buddy towed us to his shop. Got reading about it online. We switched out Throttle body. Buddy messed with it a bit unplugging relays and connectors and it ran again like nothing happened. I drove it back home shut it off and it wouldn’t start about up checked the ruse it blow the eccs1 again replaced it and it wouldn’t had to  unplug the engine relay and plug it back in it started took it for a drive and it was revving weird and shifting delayed it will only seem to blow the fuse after you drive it and it idles and sometimes it doesn’t at all 

 

we’re thinking it’s the ecm but want to see if anyone has any ideas before we spend $600 on a ecm 

[Slartibartfast]

That's a whole lot of weird. I don't know the R50's engine control all that well, and the diagram in the manual isn't as helpful as I had hoped--it shows lots of fuses, but doesn't label them, so I don't know exactly where those two are supposed to send power. EL shows a bunch of fuses, but I don't see any labelled ECCS1 or 2--though considering Nissan calls the fuel injection system ECCS, yeah, makes sense they're for the computer. The question is whether they're powering the computer itself, or something the computer controls.

 

I'd be surprised if the computer was messed up enough to blow fuses, but still sorta working. Is anything else not working? Any obvious damage to the wiring harness? Anything plugged into the OBD2 port? Any prior flood/water damage? Any trouble codes? I'd try and run down anything else it could be, including checking ground points, before dropping $600 on a computer.

 

Also IIRC the computer has to be programmed to accept the body control module, or the anti-theft system gets pissed off. I think there's a relearn procedure for the throttle body, too.

 

If you haven't yet, download the '04 service manual from Nicoclub. It's late enough that an annoying amount of it is just hand-holding for using a dealer diagnostic system that you don't have, but they do slip up and include actual useful information here and there.