switching ecu's need help!!

[talontsi02]

ok to make a long story short, i shorted out my stock ecu out of my car (95 tsi awd) and tried to put in a 98 gst ecu in its place, i plugged it in and it wont start. it will just turn over and stutter while doing so. at least my old ecu will start it and have a crappy idle. so what im wondering is what ecu is compatible with my car? i thought all the 2nd gen turbo ecu's would work but i guess not.

longer story:

i fried my ecu by trying to patch up o2 sensor wires and one of the hot wires touched ground and my ecu immediately threw 4 codes. i could be wrong but they were something like p0100 p0105 p0110 (air temp/coolent temp/blah blah blah) correct me if im wrong but im pretty sure that the ecu is fried. whats my best bet? anyone want to trade for a 98gst ecu? hehe

any help is greatly appreciated. thank you once again

 

[ADrewzki]

I believe that 95 and 98 cars have different methods of triggering the CAS signal. For 95-96 cars, it's a separate sensor that normally sits behind the intake cam gear. 96+ they replaced it back to the CAS. That may be an issue when trying to use another ECU from another year. Also, it sounds like you shorted out a few things you weren't supposed to. If nothing fried, more than likely you can reset the ECU by taking off the ground cable to the battery and reconnecting it after 10 minutes or so.

 

[talontsi02]

hmm... very interesting, sounds logical. so would ANY 95-96 turbo ecu work with my car? (auto/FWD/AWD) anyone else have any thoughts on any of this? thanks.

 

[96whgsx]

From dsmlink.com:

Any turbo model DSM EPROM ECU will work identically for purposes of running DSMLink. You do not need to concern yourself with whether the ECU came from AWD, FWD, automatic, or manual transmission car. The one exception to this is for the 1G automatic cars.

 

[talontsi02]

From dsmlink.com:

ok so my next question to you is, how come the 98gst ecu didnt work when i plugged it in? it didnt even start or anything. i find it impossible that so many sensors would go out especially when the o2 isnt hooked up to any of them as far as i know.

 

[talontsi02]

also does anyone know if its repairable?

 

[NitrousPete]

There are companies out there that rebuild ECU's, like http://www.ecmtogo.com/ for example. I do NOT know anything about them, only that I've heard of them before. Mods if this conflicts with a sponsor interest I apologize in advance.

 

[NitrousPete]

I believe that 95 and 98 cars have different methods of triggering the CAS signal. For 95-96 cars, it's a separate sensor that normally sits behind the intake cam gear. 96+ they replaced it back to the CAS. That may be an issue when trying to use another ECU from another year. Also, it sounds like you shorted out a few things you weren't supposed to. If nothing fried, more than likely you can reset the ECU by taking off the ground cable to the battery and reconnecting it after 10 minutes or so.

From the DSMLink.com website:

What does CAS inversion mean?

For 1G DSMLink, nothing. For the 2G guys, the '95-'96 style Cam Angle Sensor (CAS) sends out a signal that's electrically "inverted" from other DSM cam sensors (1G or '97+ style). When you put a '95 ECU into a car with a non-95 CAS, the ECU ends up swapping the firing order of the injectors. In most cases, this produces very little noticeable difference in drive quality. But we offer the option to invert the CAS signal anyway just in case. You can selectively invert this signal with the DSMLink software as you wish. You will still need to swap your spark wires, though. We can't control spark firing order in the EPROM at crank time. So even with CAS inversion, you still have to swap plug wire 1 with 2 and 3 with 4.

In other words, it should still start, but might not run 100% perfect.

 

[daren_p]

Yes it will run, maybe not 100% because of the CAS. But you have to swap the plug wires as the firing orders are different. 1 with 2 & 3 with 4.

 

[talontsi02]

Yes it will run, maybe not 100% because of the CAS. But you have to swap the plug wires as the firing orders are different. 1 with 2 & 3 with 4.

ok that explains a lot actually, cause when the engine was turning over without actually igniting it would studder as if it were backwards or just flat out confused.. i think im going to just sell the 98gst ecu and buy a 95-96 ecu. im pretty sure that will solve all my problems?

 

[daren_p]

Ya you can do that but why don't you just swap your plug wires around first to see how it does run before you go spending extra cash on an ecu? I don't think the inverted CAS signal makes much of a difference but the only way to find out is to try it out. Your main problem is the wrong firing order between the two ecu's and switching the plug wires around will solve this

If your origional ecu is an eprom unit you might want to talk to dave at dsmlink, he is pretty good with repairs & he could probably tell you if its worth fixing, or if it would be better just to buy another one.

 

[talontsi02]

Ya you can do that but why don't you just swap your plug wires around first to see how it does run before you go spending extra cash on an ecu? I don't think the inverted CAS signal makes much of a difference but the only way to find out is to try it out. Your main problem is the wrong firing order between the two ecu's and switching the plug wires around will solve this

If your origional ecu is an eprom unit you might want to talk to dave at dsmlink, he is pretty good with repairs & he could probably tell you if its worth fixing, or if it would be better just to buy another one.

ok cool thanks a bunch. i heard from a couple people that it wouldnt run 100% unless i inverted the cas? is that true? and if so how hard would it be to do that? sorry if its a stupid question i just haven't experienced this part of my car breaking yet haha

 

[daren_p]

ok cool thanks a bunch. i heard from a couple people that it wouldnt run 100% unless i inverted the cas? is that true? and if so how hard would it be to do that? sorry if its a stupid question i just haven't experienced this part of my car breaking yet haha

To invert the CAS, pretty hard I think unless you have dsmlink. Its an option you can turn on/off in dsmlink but I don't believe you can change it otherwise.

 

[talontsi02]

this is just an update for everyone else that has the same problem as me for some odd reason.. my car is up and running now and it runs perfect.. i had to switch the firing order by changing around the spark plugs and now everything is good.. thank everyone very much for helping me out with this.. it couldve been a lot worse then what it already has.. thanks again. i love me some dsmtuners

 

[razorawd]

Glad to see everything workes out for you congrats

 

[geddytrams]

Ok, so here is a minor issue. I have just bought a 96 eagle talon tsi awd with a blown eprom ecu. It is a manual, and i need to drive it home, so i'm in search of an ecu that i can plug in so that i can drive it. Having been part of the dsm community for a while already, i have some friends with ecus who were offering to lend them to me, but it seems unclear as to whether or not a: 91 gen manual awd ecu, or a 96 auto tsi awd ecu will work for the purpose of getting me home. Many thanks for anyone who can help me out.

 

[Dream On]

Ok, so here is a minor issue. I have just bought a 96 eagle talon tsi awd with a blown eprom ecu. It is a manual, and i need to drive it home, so i'm in search of an ecu that i can plug in so that i can drive it. Having been part of the dsm community for a while already, i have some friends with ecus who were offering to lend them to me, but it seems unclear as to whether or not a: 91 gen manual awd ecu, or a 96 auto tsi awd ecu will work for the purpose of getting me home. Many thanks for anyone who can help me out.

The 96 auto one will work just fine.