Well, after a few times of my 2003 g35 coupe randomly not starting, it has finally stopped all together. When I insert the key the lights on the dash are slow to turn on, and sometimes the entire center pedestal doesn't either. When I turn the key everything either flickers and there is a clicking noise from below the passenger dash or nothing at all happens. I have a new battery so it's not the issue and all fuses are checked good. Thinking an ECM? If so, when I buy one off the exact make and model do I need to have it reprogrammed? Thanks for any help.

 

hmmm that sounds soo much like when my battery went bad. the lights and weird clicking in dash. double check your battery and make sure the posts are clean and making good contact.

if you have to get a new ECU. yes it will have to be reprogrammed to your key. cause the security feature in the ecu wont let the car start if the codes done match.

 

ECU is not the one that lets your car start. It's an immobilizer unit on your ignition key. Any immobilizer unit could be put on and programmed to the key, it does not have to be the same unit that came with the ECU.

As far as the ECU goes, you need to have a same configuration ECU. If your is AT you need one off of AT, if your is MT you need one from MT.
I can guarantee that any ECU from 03 or 04 will work on your car as long as it came off of same transmission. 05 and up I'm not sure about.

If you can pin point the problem to the ECU. I got one for 04 automatic transmission. It should match yours if you are also automatic.

It would not hurt to check the battery cables and fuses on the positive battery cable, Make sure they are all good and not burned. Check the main ground wire too, it might have gone loose or corroded and not making a contact.

 

I was having gremlins appear and I went to my bay to find my positive battery cable loose... Was recently dealer services during an oil change lol.

The simplest things getcha.

 

It was the ground to the chassis for the battery the whole time! Thanks for the help.

 

Glad I could help, you owe me a beer.

 

Yea, that ground wire is crap. That was one of the first things I replaced on my car when I bought it almost 9 years ago. My wire actually broke off and when I saw how flimsy it was, I just bought a thicker wire and put a new ground in.

 

Did your G throw the U1000 code?
Mine did and then made my transmission act really funky.

Just trying to find a diagram of where these "grounds" are that I have to check...Where exactly is that one beneath the battery?

 

Guys this is my first post on this site and I'm not sure how to go about it so please bear with me. I decided to post under this thread since the issues are similar.

Two weeks ago my car wouldn't start. I thought it was the battery so I boosted it yet nothing. The engine cranks up but doesn't start at all.

Long story short, after almost 1.5k spent on diagnostics and/or different mechanics, I now need to change the ECM. The mechanic asked me to find an exact match on the numbers which is like finding a unicorn.

I've found two that match mine (same model year and make) except for the last four digits. Will this work on my car? Does it need to be reprogrammed? Or do I absolutely have to buy a new ECM?
Mine is BN MEC65-210-B1-4X25
The closest i found was: BN MEC65-210-B1-4Z20

The Infiniti dealership says it'll take 2-3 weeks and will cost $1335 before taxes.

Btw my car is a 2005 g35 sedan. Automatic, rear wheel drive.

I'll appreciate any quick replies.

 

Trade it in for a new vehicle and kiss your wasted $1.5k goodby

A new vehicle comes with all new parts and a warranty

Lessons learned are sometimes expensive

Telcoman

 

Im replacing my ECm as well, looking for the re-programing instructions. Anyone have it? share a link?