Hi guys,
mom new to this group i just literally joined just now. So forgive me if this is something that has been talked about previously. I tried to search the forum for this topic but i couldn’t really figure out how to navigate it so sorry in advance of this has been talked about.

*I AM MECHANICALLY INCLINE* just putting this out there so if anyone has any pointers on where to go and what i may have missed to check would be greatly appreciated!!! I owned the car for 4/5 months an driven it for a week 🤦🏻‍♂️ I’m completely flustered and beyond agrivated with this car. PLEASE SOMEONE HELPP!! Lol

I’m just going to give the run down about my 2004 g34 auto coupe. With 95k miles clean title. And the issues it’s having and had. Sorry in advance for the long description i just want to give the whole story.

i bought the car not running. Sight unseen delivered to my house. The guy told me everything was fine with the car and was driving home from work one day an the car stalled on him and never turned back on. He was a kid in college. So didn’t have much mechanical skill to diagnose he was honest with me.
so i got the car and it was a crank no start condition. Working on previous nissans before my first thought was crank sensor since fuel pump was priming was a no spark issue. So i scanned the car and got a cylinder 5 misfire, cam sensor bank 1, and a intake air temp sensor i believe.

so i went to the Autoparts store grabbed 2 cam sensors a knock sensor and a maf just to change them i got the car for 800$ so i didn’t mind changing them. Figured it would be a 2 for 1 fix the issue and do a little preventative maintenance. But long behold that did not fix the no start issue. The car did have a aftermarket alarm system that was taken out and in a ziplock bag when the car got delivered to my house that’s what the kid did thinking it was due to that the car wasn’t starting since he said he had an issue with the alarm it would act up an the car wouldn’t start. So that was removed. Now after replacing the sensors i checked for 12v on both cam sensors, and crank sensors. Which they had. I checked for ground which they had. And it wasn’t giving a signal. So after cleaning all the grounds trying again nothing. I have a buddy that has a junkyard and happen to have a 2004 g35 coupe auto in the yard with the key. So i lucked out i went there got everything for 150$ the igniton and key, the imbolizer. And the pcm and ipdm. Plugged them all in and bam car fired right up. It had the misfire so i changed cylinder 5 coil pack and all was well.

A week or 2 weeks go buy everything fine besides the slip and vdc slights where on the whole time and if i didn’t hit the button on the dash to illuminate the vdc on the cluster then the car would stumble and shake like the abs was pulsing the breaks. But the car has mismatched tire sizes and needed brakes so that was another issue i had to tend to. But if i pressed the vdc the car ran pretty close to normal besides the long shifts ect but the car was running for now.

then randomly the car started to misfire and almost loose all power i came to a stop and BAM! car stalls and the fans kicked on. Lost communication with the pcm. Let the car sit a bit and wiggled some of the connections on the ipdm and then the fans went off and the check engine light came on again like it should. Fuel pump priming again.

so i scanned the car and nothing poped up. No security light nothing. DOES ANYONE NO WHAT COULD OF HAPPEN AGAIN!! When i replaced the pcm i noticed it was not the original pcm because it had junkyard writing on it. So i am not sure if this was the same problem that happen before and ir happen again. Or did the kid that i got it from try an fix it and just pulled the oem pcm out and put a new one in thinking it would just start up with out having it programmed with the key. So if anyone has any input or anything that can help me get this thing back up an running i would be over the moon. I bought the car secretly for my girl to surprise her when she came home from out of state from helping family and now i have a dead g35 sitting in the driveway 🤦🏻‍♂️🤦🏻‍♂️ She didn’t have a car so i figured it would be a easy fix but of course nothing goes that easy.. usually i get lucky when buying cars that aren’t running i was scared the motor was bad mechanically but thankfully it’s good it’s just a nightmare of electrical that I’m not the best in. But i no the basics. ANY HELP WILL BE GREATLY APPRECIATED!!

 

For starters, these engines do not play nice with aftermarket cam/crank sensors, Hitachi is the OEM manufacturer so only use those or Genuine Nissan Parts.

I would pull the junkyard sensors and use those, it's VERY common for an aftermarket sensor to either not work at all or only work for a couple weeks.

However it does sound like you have a wiring issue, lets back up a little though and verify EXACTLY what components you changed out on this car. This car uses the IPDM (engine bay fuse box) the Body Control Module (BCM driver/left footwell), and the Electronic Control Module ECM (passenger/right footwell).

Exactly WHAT did you replace. You cannot just plug-n-play swap an ECM or BCM, they are programmed together with one another as part of the anti-theft NATS/IVIS system.

Here is a link to the factory service manual, the document starts at FWD - Forward.

https://www.nicoclub.com/infiniti-service-manuals

There is a red LED light to the left of the instrumentation, when you crank the engine is the light SOLID RED? This means a nats spark/fuel interlock and is commonly caused by the BCM not recognizing the RFID chip in the key.

 

Yes you can, i went to the junkyard grabbed a igniton the ipdm and key the pcm and the imbolizer all from the same 2004 g35 coupe i found in the yard and put it in my car and it fired right up first turn of the key. I also had a pats issue so it fixed all the issues i was having at once but was short lived. So you can do that. Dont mean to come off rude I’m just stating it can be done because i did it and it worked. And i still have my ignition my key my pcm and my imobilzer on my tool box from my car that i took out and replaced it with the ones from the junkyard so that does work and you can bypass going to a dealer and getting the car re programmed when you take all them components and put them in the car you are working on if someome ends up needing a pcm you just have to be lucky enough to find them all in the same car with key like i did.

And yes pretty much that’s what happen i bought brand new cam sensors from the Autoparts store the car ran for a couple weeks and then it died on me like the guy i bought it from said happen to him.

but this time i noticed when it died i lost my check engine light, the fans kicked on the fuel pump DIDNT prime. And then after it sitting for a bit that went away my fans didn’t kick on no more the check engine light came back on the fuel pump turned back on but was still a crank no start condition.

but yes before i changed all that i replaces the cam sensors the crank sensor the maf an nothing then i went to the junkyard grabbed them parts i just stated poped it in my car an bam it fired up.

so i was to source the problem if i can in the harness before i change all the pcm,ignition and key, imobilizer, and ipdm again and the same thing happen again in a couple days or weeks. You no. I’m not having to pay for those parts since i got a warrenty on them so i can just exchange them. That’s what I’m going to do.

but do you have an idea on where to start checking,

what should the cam sensors ohm out at if there good, same wirh crank sensor. And when checking the power/ground and signal on the cam sensors if the pcm is doing its job then it should get its ground right and then what a 5v signal to the pcm or from the pcm to the cam sensor.

and what should the crank sensor be giving off ?


or what do you think i should start with. A check list and go threw one by 1. Is there any diagrams out there that would help me pin point this. Any help will be appreciated. I’m beyond agrivated with this car. Went from being a simple fix OR I THOUGHT to a complete nightmare 🤦🏻‍♂️🤦🏻‍♂️

 

Ok yes if you swapped out BCM, ECM, and took the keys from that vehicle then yes on paper it would work since those components are all programmed together already. The programming can be done with either Nissan Datascan 2 or the dealership Consult-II. IPDM doesn't have any programming it's just essentially a fusebox and a CANBUS relay.

What is this component that you keep calling the PCM?

BCM is in the driver footwell, ECM is in the passenger footwell.

Ford uses a Powertrain Control Module (PCM) which usually bolts to the transmission and is basically Nissans version of a Transmission Control Module (TCM) which can be either mounted next to the ECM for 2004.5+ or inside the transmission for 2003-2004.5 (I'm guessing you're talking about the ECM which handles engine management and step 2 of the NATS/IVIS system).

What is this component that you keep calling the immobilizer (I'm guessing it's the body control module which handles all chassis function as well as the first step of NATS/IVIS security).

It just helps to keep the language all consistent.

You can't use a digital multimeter to check the signal from the cam/crank sensors, they're hall effect sensors that require the use of an oscilloscope to read the frequency signal they send back to the ECM.

First verify you don't have a NATS/IVIS interlocking the car, while you have the key on start and the engine is cranking that little red LED light on the left side of the dash SHOULD NOT be on. If it is then the BCM doesn't recognize the key and you have a NATS/IVIS issue. This is usually just the car not recognizing the key, the dealership can reprogram it (tow to Nissan, pay a 1 hour service fee) or some locksmiths have specific software that can program it, this can also be done with Nissan Datascan 2 on a laptop with a VAG interface cable.

Next check your tachometer while cranking, does it move a little, if the tack doesn't move at all when the engine is cranking strong (not a weak almost dead battery crank, it probably won't move regardless) then it's probably a fried crank sensor (CKP). The cam phase sensor (CMP) is a little harder to test. Only replace these items with Genuine Nissan Parts or Hitachi (the OEM manufacturer) it's a widely known fact that ALL other sensors will probably not work, or will rapidly fail on this engine. Every once in a while someone gets lucky and their aftermarket will last a year or two but it is VERY UNCOMMON and to get the car running I absolutely would not use any aftermarket sensors on it.

Is the vehicle throwing any codes on an OBD2 scanner? Pending codes will not turn on the check engine light.

Did you verify the replacement ECM sticker was EXACTLY the same as the one that you removed from the vehicle, the MEC##-### number needs to be the same. There were quite a few chassis options configurations for the G35 and if the donor vehicle had the EXACT SAME setup (coupe/sedan, sunroof, etc) and was from a suitable donor year (2003-2004.5, 2005-2006 for sedan or 2003-2004.5, 2005-2007 coupe) with the exact same transmission (I'm assuming since you haven't mentioned anything about the TCM that we're dealing with a 5AT 2004.5+) then you should be ok with the IPDM/ECM/BCM/key swap you did.

If your chassis/package configuration is NOT the same I would put the old components back in, make sure to identify them as a matched set, like a sharpie x on the existing set, just so they don't get mixed up because they will not work without programming the ECM/BCM/key together with NDS2 or Consult-II.

Next verify spark, pull a coil pack, pull the spark plug, plug the coil back in, put the spark plug back into the coil and with a LEATHER GLOVED HAND or use a ziptie or something hold the ground strap of the spark plug exactly 1/4" away from the metal on the intake plenum (yes it has to be exactly 1/4" or you risk damaging a coil pack). Now crank the engine and watch for spark.

If you DO have spark then it's possible you're simply out of gas, these gas gauges are notorious for failing and showing 1/2 tank when actually you're bone dry empty.

If you DO NOT have spark then it's either the crank sensor, a cam sensor, or NATS/IVIS lockout preventing spark/fuel.

My gut is telling me it's those aftermarket sensors you put in, I with you could fully understand just how high the failure rate was on those things. These ECM's are VERY particular about sensors, Hitachi, Genuine OEM Nissan only. Yes they cost $50 apiece, but they will actually work.

 

GM's term for ECU used to be PCM, not sure if it still is. Maybe that's where they're coming from.

 

Oh crap yes I’m sorry. I am just used to calling it a pcm an yes i do have 3 trans ama lol. Power train control module. Ecu, computer you no what i meant lol.

but yes that’s what i am referring to. Sorry for the confusion

 

cleric670 thank you for the break down. Yes i have 2 terminators a fox and a 99 cobra. I just have a wide variety of cars. Sorry for the terminology error.

but yes it has fuel the pump primes.
the security light is not on when cranking
i do not have spark but i have power and ground at the coil.
And i get 0 rpm movement while cranking the car


And i just bought a brand new set of cam sensors and crank sensor. Yesterday
i went to buy the hitachi ones but the angled/drivers side didn’t exist in hitachi. Atleast at the store i went to. But they had the crank and the pass side hitachi cam sensor. I didn’t want to miss match so i just bought all 3 of them new. An nothing.

im getting weird intermittent issues. Like when it stalled the day this happen the fans kicked on out of no where and no check engine light and no fuel pump.

and then i disconnected the battery real quick and then re connected it and cycled the key and it went back to normal with the check engine light on and fuel pump priming.

And what’s weird is the car ran on a set of aftermarket sensors until it didnt lol. So i warrantied them out yesterday and poped them in and nothing. Even tried poping in my other ipdm and nothing.

So ya... super lost. The cam sensors have power and have ground.

So do the coils but it did not spark.

so ya I’m stumped. I’m guessing i have a harness issue somewhere from the computer to the cam sensors or to the knock sensor.

because I’m not sure what else it can be i got fuel, it’s not a security issue, don’t have spark, and has all new maf, cam sensors and knock sensor.

Is there a pin out available that maybe you can post up here so i can go threw the harness and check Continuity. And make sure i have power where i should i have power and ground where i should.

and do you happen to no what should be the desired voltage for the signals from the cam sensors and from the coils. Maybe that can help determine if it’s a computer issue or not. That’s where I’m leaning towards.

because it has had 3 different computers in the car that i no of the factory one that the car came with. Then the 1 that was in the car when i got it but the car didn’t run it had a security issue. And then this one that i put in the car and it ran.

so I’m thinking if we go threw the rest of these tests and dont figure it out. To pop the computer the ignition the key and imobilzer that i got the car with when it was not running and then get them to program that and see if it fires up.

but i want to figure out what is causing all these computers to fail in the first place i must have a huge short somewere. I just don’t get why it took a couple weeks to fry this computer if that’s what turns out that happen.