Alright my ECM is gone on my AWD and I am looking for a replacement.. and I have one but I don't know if it will work.

So here is the story, I got the computer out of another 90 TSI but the wiring harness at some time had been swapped (don't know if it was from another 90 or some other year or what). I also have a 93 TSI computer. So my question is will only another 90 TSI computer work in it since I have been told 90 is different from the other years or will some other computers also work? How can I tell if the ECM is a 90 or not without plugging it in. Will the car run at all with the wrong year ECM? Finally how much would it cost to have my origional ECM rebuilt? Thanks alot guys

 

In case you guys didn't know it's a 90 TSI AWD.. but also does it make a diffence if the computer is from a fwd or awd?

the # on the computer that is in the car is MD145903

 

So no one knows anything about computers?

 

Any 90-94 turbo DSM ECU will work. The car will run with anyone of them. However, the 91-94 have two pins swapped (six and fourteen). One is for the idle switch and the other is for the Air Flow Sensor filter reset. In any event, the car will still run with or without swapping the wires in your harness.

The only difference between the FWD and AWD ECUs is, I believe, two resistors. They affect fuel trim marginally and you will not notice the difference. Ideally, you should acquire either a 90 AWD ECU or an EPROM.

Here are the ECU codes:

Manual AWD
3/89-6/90 - MD145903
6/90-6/92 - MD166262
7/92-5/93 - MD193299
6/93-5/94 - MD304484

California Manual AWD
3/89-6/90 - MD145902
6/90-6/92 - MD166263
7/92-5/94 - MD193295

Automatic AWD
6/90-6/92 - MD165531
7/92-5/93 - MD193300
6/93-5/94 - MD304485

Californial Automatic AWD
6/90-6/92 - MD165532
7/92-5/94 - MD193296

Manual FWD
MD128625
6/90-6/92 - MD166260
7/92-5/93 - MD193297
6/93-5/94 - MD304482

California Manual FWD
MD128623
6/90-6/92 - MD166261
7/92-5/94 - MD193293

Automatic FWD
6/90-6/92 - MD165529
7/92-5/93 - MD193398
6/93-5/94 - MD304483
MD193298

California Automatic FWD
6/90-6/92 - MD165530
7/92-5/94 - MD193294

 

you can tell very easily if its a 90 or 91+without opening it up.just plug it in and rev it up to about 3500 to 4000 rpm and if the tach goes craazy up and down then its a 91+.If not then its a 90. reason being is because of the tach adapter on the coil pack between the 2 or different.

 

Thank you, I appreciate it.. the car should run fine though without any real problems if it is the wrong computer right? I just want it to get me by for a couple weeks until I have the cash to put the right one in.

 

Yeah...

I ran the following ECUs in my '90 Talon TSI without any noticeable differences:

'90 FWD MT
'91-'94 FWD MT
'91-'94 AWD MT

 

Also awd ecu's have no speed limiter. Atleast thats what ive heard, not to sure though because for awhile I had a nonturbo ecu in my 91 and was seeing 130+ speeds.

 

 

Alright well I have a 91 awd and a 93 awd ecu which one do you guys think I should use?