I have done alot of research while the org was down and I have concluded that 99's can use an ECU from 95-96. The ECU harness is the same, there are a few pins that are differnent for Evap. The NVIS system is not connected to the ECU like most people think. The 99 ECU Pin-out shows a pin for hte ignition switch, but it is the same pin as the 95-98.

Now, Can anyone tell me why they can't use hte ECU's from previous models? I am sure they will get a CEL like the 97/98, and we will have to do something about teh EVAP, but the ECU should will work.

99 ECU doesn't use pin11 as Fuel Pump relay.
99 Pin 27 is a "PNP switch" and in other models it does EVAP stuff
99 Pin 35-36 is EGR stuff, those arn't used in 98pre-
99 Pin 53 is swirl vavle, which is not in 98pre, also it's not needed.

98 Pin 110, 118, 114 are EVAP stuff, these are not in 99.

 

Looks like with a bit of wiring the swap can be done. Seems easy enough, but barely any on on the ORG trys something that has been "ruled" not possible. If I had a 99 I'd try something, but I dont. SOmeone should have at it.

 

Its only those pins that are differnet, the connector is the same, I know the 99 has a differnet type of EVAP, but that is all, I am pretty sure it will not be a problem.

 

im going to run a 96 in my 99 im sending it in to jim wolf for the reporgamming it needs.from what some people say some people have run a different ecu in there 99s but i havent heard of anyone doing it.mine will be sent in monday and when i get it back we will see if i wasted 600 bucks or not

 

Wouldn't it be best to get it working stock so you aren't out $600 if it doesn't work out? I guess you could get most or all of that back by reselling it.

 

i thought some 99's used ecu's from 2k's which have a differnt wiring harness, maybe thats the issue, SOME 99's have - 99 ecu's some have + 99 ecu's?

 

yeah it would be nice to get the 96 ecu working in the 99 first but you cant because the immobilizer between the ecu and the key work allow the car to start

 

It's a job that aboslutely sucks when you don't have a lot of room to work with.

I say that someone with a 99 should just drive around for a day with a 95-96 ECU. That's the only way for one to get confidence that they will be able to use the ECU.

 

well like i said before in my last post i have a 96 ecu and i put it in my 99 and it will not start..jim wolf said that they need to reprogram the ecu and it will then work in the 99. mine is going to them on monday

 

What if you dissconnect the immobilizer

 

im going to have to try that today. i spoke with ben at jim wolf and he said that the 96 ecu should start the car with no problem.i might have a bad ecu so im going to try it again today and see what happens.he said the only thing the do is put the program in and that it. no special wireing or anything.also said that yes you lose the immobilizer with the 96 ecu. if it dont work today im going to order another ecu.

 

The thing is, that I have the 99 ECU pin out from the Nissan FSM and it doesn't list anything for hte immobilzer or anything like it. Just like I said above, it has a pin for the ignition switch, but so does 95-98.

Also, when you had hte 96 ecu in your car and you tried to start, did the security light in hte dash blink(I think it is a green key)?

 

no the security light was solid which i think was the problem. maybe if i dissconnect it from the system it will work. im going to work on this weekend and try to get it running. but i might also have a bad ecu also. so if no go ill buy another ecu and try that one also.ill let you know what i find out

 

well here is the news i put the 96 ecu back in and car will not start my security light stays bright solid. so im out of luck i tried pulling fuse`s and other things but car will not turn over.. guess im going to send in the ecu for a test to see it it really works or not.monday ill talk to jim wolf again and see what they say

 

Do you know where the imobilzer is?

 

Chuck: sounds like that fuel pump relay is not being powered. Thats the only difference in ECU's that would cause the car not to start. Did you re-wire the plug for the 96 ecu?

deezo: You are right it sucks, room? what room....hehe. I had one hell of a time doing the manual fan switch wiring. Then putting the ecu back!~? what a PITA.

 

Pin 117 is the fuel pump relay on the 99 harness. It is a black/pink wire. Try to move it to pin11.

 

from the fsm it looks like the nvis system connects to pin 17 on the ecu

 

no i dont know where the immobilizer located. thanks for you help guys. i will try moving the pins to different locations sometime this weekend if i get a chance.im willing to do anyt it takes to get this damn thing working.would love to have it before i go boosted

 

In mine version of the 99FSM, pin17 is not used. It jumps from 16-18 in the FSM.

 

kevlo, look at the section dedicated just to the nvis system, it in el-295

 

Dissconnected some of those and see if it works.

 

yeah i think thats my problem the fuel pump ben from jim wolf said that i wouild have to move to . so if i get some time tonight i will try it and i pray it works. if it does the ecu if off to jim wolf.. thanks for all your help guys.

 

Damn you Kev. You've been using me. NOOOOOOOOO!!!!!

 

Only for a good purpose.

Because of us, 99's might finally use aftermarket ECU's

 

Here is what you do to a 99 maxima ecu connector harness to convert to 96 maxima harness, first move swap the input pins for the crankshaft position REF (CRPS REF) from #46 + 47 to empty pin slots #44 + 48. Next take the Camshaft Position Sensor (CMPS PHASE) from #48 + 44, and move to empty pin slots #46 + 47. Next step is to remove the fuel pump relay from pin #117 then move to pin #11. Now you have to remove the Park/nuetral switch from pin #27 and place it on pin #22.
These steps should allow you to start the car however you will forever have a CEL for the EGR soleniod, EVAP purge volume/control, rear heated o2 sensor, AT signal + diagnosis (if the ecu/car is auto). Otherwise everything else is the same.

 

you know what's weird? I had those exact same codes (no more, no less) when I checked my codes just prior to shipping my JWT ECU off to the guy who bought it from me. I didn't really think any of it was strange except for the AT signal code because the ECU was supposedly the stock ECU that my car came with from the factory that I took out of my car and shipped to JWT...

 

Holy shiat, JWT switched your ECU for an auto and sent you that crap? That's what it seems like.

 

I don't believe that to be true because I have used an auto ECU in my car (and I'm currently using an auto ECU) and you get ALOT more codes than just the single code I got with my JWT ECU and there are also some subtle differences in how the car reacts when you go from neutral into gear or from a gear into neutral, it blips the throttle with an auto ECU. Also when coasting to a stop if you have the car in gear with the clutch depressed it will idle at about 1200 until you come to a complete stop and then will drop down to normal 650ish idle. I had none of these issues with my JWT ECU, just some random code that I never knew was there until I decided to check my codes right before I sold the ECU.

Also I can't remember for sure but I *think* I put a mark with a magic marker on the side of my stock ECU before I sent it in to JWT. It was a long time ago so I really can't remember if I did or not, but that's something I would do just because I'm weird, and there IS a mark on the side of the ECU that was made with a magic marker.

 

How would the 96 ecu in turbo 99 with mevi be affected with the S-AFC?

 

nevermind then..........

 

So here it is, now we know what to do.

 

well i guess you read from above the only thing you are doing in moving the fuel pump relay. which i did and i car hear it turn on when i put the key in but car still will not start

 

Well the car won't start prob becuase of the crank and cam sensors.

 

I tried the above advice from Nismo87SE, but the security light stayed a solid red, indicating there was some type of problem. I'm in the process of talking to a nissan mechanic I know to try and figure out exactly what the NVIS/NATS system does to disable starting the car and get rid of all that crap. The other problem is that there is no wire going to pin #11 on the 99 harness, so you can't even splice that in without taking apart the actual harness. I believe it's just a switched ground though, so you can probably wire it up to a relay or something.

 

basically the red solid light is sying is there is no security system in the car. cause the older ecu didnt have they key in the chip like the 99s do.i wired it up last night and didnt have any luck with the fuel pump. you can hear it turn on when you go to start it but thats it

 

if i cant get it to work tonight im not going to bother with it anymore. im going boosted and will get my low-mid end power back. after loosing it from putting on the mevi.but will lose the 800 plus redline increase from the ecu. thats all i wanted it for anyways

 

Did any of you 2 dissconnect the NVIS? I posted the pic of where tehy are.

 

well I'm not exactly sure where/how to do that. maybe someone can make sense of this...

 

Dissconnect the harness that goes to the Nats IMMU or the NATS ANTENNA, and see how the car responds. Try one at a time and then do both.