ECU Cooked

[SnoopySLR]

I think I need a new ECU.

Pin 2 is for signal for Coil #1, and its getting nothing out of the ECU. Pin 3 is for Coil #2 and its getting signal fine, just not Coil#1.

If anyone has a solution to this that might prove the ECU isn't bad, let me know.

If anyone has an ECU for a 97-99 N/T 420a, let me know.

I need this car running by next month this time. Big car show I gotta get to, plus wouldn't it be nice to have a DSM that isn't just a garage decoration

 

[XMasta19]

hahahah...mine has basically been a garage ornament since last august.


There are quite a few of us with "possible" ECU problems...make sure everything is checked etc, it's a known problem where people just think their ECU is phucked and it ends up being something else. I've been troubleshooting wires on my car for over a month now trying to find out what's wrong without just buying random parts. Then again, I'm in alaska...not a guy right down the road that I can just borrow his 95 mtx ecu or random sensors to test out on my car.

 

[SnoopySLR]

well my knowledge of our ignition system is this

Cam Possitioning sensor detetects TDC, sends that signal to the ECU, the ECU then sends that signal to either coil 1 or 2 depending on which fired last. If I'm in error, please correct me.

I had wondered if there was 2 magnets in the cam sensor. I talked to Cory at Modern Performance and he didn't think there was. He was pretty sure that there was only one.

I don't want to get a new ECU unless I have to

 

[bullettdsm]

Hey Snoop,

I wish you luck on that one. Not to be a "negative Nelly" (yeah, I know ###gy term) but I was looking a while back when I was trying to get through emissions with my AF/X (it turned out I went through with it) and I came up with pretty much no 97 ECU's available (and that was watching on 2gnt also). Is it worth it to send it out to someone and have it checked out? There is someone on the site who does this work relatively inexpensively. I dunno, do caps usually go on our ECU's? I know the 1g turbos do. That's pretty easy to look at. Not too hard to pop the ECU and see if it smells bad. If it stinks or you can see the crap around the caps that would at least verify it for you. Just a couple of thoughts.

Good luck,
MB

 

[SoilentGreen98]

I'm seeing this is being more common than I thought it was. I fried my ECU back in October/November and I know someone else with a 98 N/T that had the same problem. Best of luck to you man.

 

[SnoopySLR]

anyone know if the DOHC neon ECU works? The RT one. its the same motor, and I'm pretty sure same sensors. I know I could get one of those, my buddy is WAY connected in Neons.org

 

[XMasta19]

ASD / Fuel Pump relays, crank position sensor, cam position sensor, coil pack, blah blah back to ecu all in same loop

There is a whole bunch of checking of wires and testing for reference voltages etc that can be done...waiting for Terry to chime in. I'm at work right now, so I can't send you link...but I have a thread on 2gnt talking about my issues and it has some good things to check. There have been bunches of my car won't start threads, is my ecu dead etc etc lately. Just a heads up, not sayin that ## ECU isn't indeed cooked.

 

[bullettdsm]

Just for clarification on the Neon ECU's. Just did a search on 2gnt and the consensus is that they will not work because of pinout diffferences and different processing of the information being taken in (probably because of the 180degree difference in flow?).
MB

 

[SnoopySLR]

Just for clarification on the Neon ECU's. Just did a search on 2gnt and the consensus is that they will not work because of pinout diffferences and different processing of the information being taken in (probably because of the 180degree difference in flow?).
MB

cool, it was just a thought. thanks. Any wisemen wanna jump in here and help me out? . Where is the Dr?

 

[GSGoinFast]

cool, it was just a thought. thanks. Any wisemen wanna jump in here and help me out? . Where is the Dr?

Basically everything I have seen says that the neon ecu's do not work. Otherwise we would have a lot more options when it comes to performance ecu's for anyone that isn't a 97

 

[VelocitàPaola]

Just for clarification on the Neon ECU's. Just did a search on 2gnt and the consensus is that they will not work because of pinout diffferences and different processing of the information being taken in (probably because of the 180degree difference in flow?).
MB

The information processing wouldn't make a difference, as long as the ECU still makes the same decisions in the end.

Some Neon ECUs can work, but like it's been said, the pin-outs are different; this means you'd *simply* need to connect the right wires in the harness to the correct ports on the ECU. Notice the word *simply": cutting, matching, and splicing all of those wires is not easy, or worth it.

In most cases, the Neon ECU won't give you any performance gains. Furthermore, the effort needed to adapt one for use in a 2GNT wouldn't be any less than trying to adapt a 97 ECU for use in a 95 car (for example).

Most of the performance ECUs made for Neons will not work in our cars.

 

[GSTurbo05]

NEON ECU'S DO WORK! if anyone remembers i was having problems with my N/T. a few weeks later my ECU died completley so then i went to a pick a parts and bought a neon ecu because i couldnt find an eclipse and since neons have the same engine i bought it and put it in and BOOM it kicked up! only thing is the fan relays are different so i have to manually turn on my fans everytime i go to the car. pretty annoying! but to get to the point a neon ecu will work. if you guys can figure out how to rewire that relay so fans kick on then GREAT!

 

[SnoopySLR]

Hi doug sorry for not replying, when u were helping me but NEON ECU'S DO WORK! if you remember doug i was having problems with my N/T. a few weeks later my ECU died completley so then i went to a pick a parts and bought a neon ecu because i couldnt find an eclipse and since neons have the same engine i bought it and put it in and BOOM it kicked up! only thing is the fan relays are different so i have to manually turn on my fans everytime i go to the car. pretty annoying! but to get to the point a neon ecu will work. if you guys can figure out how to rewire that relay so fans kick on then GREAT!

So your saying a RT Neon ECU will fit my harness and everything? I can get a neon ECU easy! And I don't have stock fans anymore, I have slim fans on a switch, so thats not a problem for me.

 

[GSTurbo05]

Yup, that day i picked one up i didnt even look at the model or anything not even if it was auto or manual. i was just so desprate to get my car running that when i found a neon and saw the ecus were exactly the same i grabed it and bought it. went home hooked it up and bam my cars running. the only problem was the whole fan relay crap. hey if you can email me how to hook up the switch for the fans i would greatly appreciate it. pm me please.

P.S just remember, only because a stock neons ecu works on our cars dowsnt mean a performance one will. stock ecus from a eclipse and neon have same HP & TQ. just make sure it has the 420A in it.

 

[XMasta19]

...hmmm

 

[bullettdsm]

Snoop,

Careful where you tread here. I'm not doubting that GSTurbo05 did that with his car. BUT, you know very well how specific ECU for our cars can be. Also, what neon ECU (95 SOHC, 96 DOHC etc.) did he pick up? Plus, without at least widebanding (or logging) his car, you don't really know how well it is running (rich, lean, detonation etc.). Though I understand that you are just looking to get it fired up (as he was), let me give you a scenario;

You get a Neon ecu. It clips right in (which they do). You try to fire up your car and she does not start. Now which is it? Is it the Neon ecu is not compatable? Is it that you have another problem besides the ecu? You still don't know and you've wasted your cash on a part you can't bring back.

Another scenario;

You get a Neon ecu. It clips right in (which they do). You try to fire it up and she starts. How do you know it is running well? Does it have performance disadvantages to it? Is it ruining your new engine?

I am ALL for experimentation. I do it all the time, in the face of doubters. It is how we learn and grow. I've got a couple of major things on my engine that others have said would not work. I know that they are doing the job nicely. So, I believe that you need to experiment, but in this case are you throwing away money to (possibly) not have any answers?

Now, if you have free or very cheap access to Neon ecu's, then I would forget all my previous bullshit and go for it. If you burn something up then, hey, that's the way it goes. Just try and document what you are using etc. so that it can be repeated. That info may help others in the future.

Just my 12 cents.

MB

 

[GSTurbo05]

Snoop,

Careful where you tread here. I'm not doubting that GSTurbo05 did that with his car. BUT, you know very well how specific ECU for our cars can be. Also, what neon ECU (95 SOHC, 96 DOHC etc.) did he pick up? Plus, without at least widebanding (or logging) his car, you don't really know how well it is running (rich, lean, detonation etc.). Though I understand that you are just looking to get it fired up (as he was), let me give you a scenario;

You get a Neon ecu. It clips right in (which they do). You try to fire up your car and she does not start. Now which is it? Is it the Neon ecu is not compatable? Is it that you have another problem besides the ecu? You still don't know and you've wasted your cash on a part you can't bring back.

Another scenario;

You get a Neon ecu. It clips right in (which they do). You try to fire it up and she starts. How do you know it is running well? Does it have performance disadvantages to it? Is it ruining your new engine?

I am ALL for experimentation. I do it all the time, in the face of doubters. It is how we learn and grow. I've got a couple of major things on my engine that others have said would not work. I know that they are doing the job nicely. So, I believe that you need to experiment, but in this case are you throwing away money to (possibly) not have any answers?

Now, if you have free or very cheap access to Neon ecu's, then I would forget all my previous bullshit and go for it. If you burn something up then, hey, that's the way it goes. Just try and document what you are using etc. so that it can be repeated. That info may help others in the future.

Just my 12 cents.

MB

I can highly agree with you, it is a risk, when i pluged mine in it kicked up right away and your right i wasnt sure what year it was all i know is on my serials it end with AC i believe, my car is a 5 speed tranny not sure if thats the code for an automatic but ive been running mine close to the 1000mile mark and i havnt had a single problem it actually fixed problems, before my car was stalling alot and i couldnt figure it out after the neon ecu it went away and i havnt had a stall since then. Also my car use to idle really bad and that went away as well, besides a few rare times it still does cus of the ruined TPS wires.
Also I couldnt tell if it had a disadvantage or advantage because my old ecu was so burnt out it was as if i was driving a 3 cylinder car. all i know as soon as i plugged in the ecu it felt so strong to me .

but like bulletdsm said it is a risk and may or may not work. i have yet to have a problem with it besides the fan relay BS. Another thing i can do is pull the serial and part number from my ecu and find out which neon its coming from, if that helps any. I used a DOHC Ecu.

-Randy

 

[XMasta19]

...meh

 

[SnoopySLR]

I could highly agree with you, it is a risk, when i pluged mine in it kicked up right away and your right i wasnt sure what year it was all i know is on my serials it end with AC i believe, my car is a 5 speed tranny not sure if thats the code for an automatic but ive been running mine close to the 1000mile mark and i havnt had a single problem it actually fixed problems, before my car was stalling alot and i couldnt figure it out after the neon ecu it went away and i havnt had a stall since then. Also my car use to idle really bad and that went away as well, besides a few rare times it still does cus of the ruined TPS wires.
Also I couldnt tell if it had a disadvantage or advantage because my old ecu was so burnt out it was as if i was driving a 3 cylinder car. all i know as soon as i plugged in the ecu it felt so strong to me .

but like bulletdsm said it is a risk and may or may not work. i have yet to have a problem with it besides the fan relay BS. Another thing i can do is pull the serial and part number from my ecu and find out which neon its coming from, if that helps any. I used a DOHC Ecu.

-Randy

How was your car stalling out... cause mine stalls out sometimes when you drop out of gear to come to a stop in N. Its anoying as hell, and I've never been able to figure out what it is. Maybe my ECU has been going for while. I'm gonna try to snag a ECU somewhere. I can probably just get a buddy to let me swap to try it. Its worth a shot, so I'll see what happens.

Another thing I was wondering... if these ECU's do work... and you say the performace ones don't... why would that be? You would think if the OEM ECU works the Mopar ECU would work too

 

[GSTurbo05]

How was your car stalling out... cause mine stalls out sometimes when you drop out of gear to come to a stop in N. Its anoying as hell, and I've never been able to figure out what it is. Maybe my ECU has been going for while. I'm gonna try to snag a ECU somewhere. I can probably just get a buddy to let me swap to try it. Its worth a shot, so I'll see what happens.

Another thing I was wondering... if these ECU's do work... and you say the performace ones don't... why would that be? You would think if the OEM ECU works the Mopar ECU would work too

Im just saying the performance might not work. i have yet to try it. but yeah my car stalled out the same way. i couldnt figure it out either and i told my girl that the ecu must have been going out since way back, cus i was even stalling in gear and my car would kick back up but when the ecu completley fried it shut off control to the throttlebody my car was still on cus i had it in gear when driving down the freeway and i looked over at my girl thinking it would kick back up and nope car wouldnt turn on at all, it was DEAD! the funny thing was i could downshift and hear the rpms kick up but as soon as i pressed the gas pedal it wouldnt do anything, gauges were dead. haha. so i grabed that neon ecu and it fixed that stalling BS. I was gonna try one of the neons performance ecu's that up the rpms to 7500rpms and had more HP & TQ or something like that but i didnt wanna take the chance.

XMASTA19 whats your problem? hmm... meh...