How do I identify the right ECU

[plodder]

I may need an ECU even though they rarely fail. 1996 legacy outback.

 

mine says: 8D

22611 AC270

JA18000 DAO 5918

 

 

 

What are the important #'s here I have another one I picked up, but do not know if it would run my car. Currently it does not and I have another thread under No spark. But I only want EcU info, that iswhy I have a seperate post.

 

The other ECU is 3Q

22611 ac461

A18-000D24 6304

 

Both are out of 2.2 manual tranmissions one my car 1996 legacy, the other 1996 impreza.

I was told the ac461 and AC270are the only real important #'s. If that is true I need one with th ac 270, if ya got one.. Thanks Dann

[Fairtax4me]

22611 AC270

This is Subaru's part number, so if you want to be picky you should match that up. Honestly though, I don't think it makes a difference.

Match up what you have with the car you are getting the ECU from. Engine size, transmission type, and EGR or non-EGR. Those are about the only things that matter.

And even at that, the transmission type is selected by a certain pin of the ECU being grounded or not, which is done in the wire harness in the car, so engine size and egr vs non-egr are basically it.

[ShawnW]

Theres no reason not to exactly match it thats a very common car. That doesn't mean you couldn't do so temporarily to verify it fixes a problem but it could certainly create emissions, drive ability, gas mileage and check engine lights that would haunt you.

 

That part number is superceded by 22611AC271 so that one works as well.

 

Using car-part.com I found one that matches at a salvage yard.

Randy's Auto Parts and Towing USA-WA(Okanogan) E-mail 1-800-553-4466

 

1996

Engine Computer

Subaru Legacy 22611 AC271 A 6943 $100

 

Lots of others on there too if you do a search you can pick one closer or whatever makes it easier better for you. This was one of the few with the actual part number on the description.

[plodder]

Theres no reason not to exactly match it thats a very common car. That doesn't mean you couldn't do so temporarily to verify it fixes a problem but it could certainly create emissions, drive ability, gas mileage and check engine lights that would haunt you.

 

That part number is superceded by 22611AC271 so that one works as well.

 

SO if I'munderstanding correctly, the 2nd one I have listed should run the car if the ECU is the problem, right?

 

It came out of an ompreza with 2.2, mt, nothing special.

 

And that the important #'s are the ones, you listed, I noticed that the one At Randy's Auto had one # off, that's ok?? Thanks Dann

[johnceggleston]

if you have tried 2 ECUs, yours and another, and the car does not run then it is not the ecu causing your problem. even if it was not the perfect ECU the car would run but maybe throw some codes.

 

i am not 100% sure about this statement, but it is highly unlikely that both ECUs are bad and unlikely that the one you have, as similar as it is , would not work at least a little. if you had swapped the engines instead of the ecus the car would run so the reverse should be the same.

[plodder]

if you have tried 2 ECUs, yours and another, and the car does not run then it is not the ecu causing your problem. even if it was not the perfect ECU the car would run but maybe throw some codes.

 

i am not 100% sure about this statement, but it is highly unlikely that both ECUs are bad and unlikely that the one you have, as similar as it is , would not work at least a little. if you had swapped the engines instead of the ecus the car would run so the reverse should be the same.

 

No the other ecu came from a known running 2.2.

 

THANK YOU!!!!

 

knowing what is not wrong brings hope to my little quandry.

 

I like simple answers to simple question.

[ShawnW]

if you have tried 2 ECUs, yours and another, and the car does not run then it is not the ecu causing your problem. even if it was not the perfect ECU the car would run but maybe throw some codes.

 

i am not 100% sure about this statement, but it is highly unlikely that both ECUs are bad and unlikely that the one you have, as similar as it is , would not work at least a little. if you had swapped the engines instead of the ecus the car would run so the reverse should be the same.

 

I would have to look at a wiring diagram to be sure of this and I think you are making a large assumption. Just one ignition on wire being pinned to a different position, inhibitor switch lacking, etc would certainly cause a no start situation.

 

I think you should obtain, borrow, etc an OBDII scanner. Put the factory ECM into the car and put the key to ignition on. See if it will communicate even. If it won't I would assume its fried.

If it will start troubleshooting no start.

 

For this I would pull a plug wire off the coil pack and see if you are getting any spark.

[plodder]

Thanks, I have another posting for the no spark issue. This was "ONLY" for the porpus of ecu identification.Please, if you have any other insights on this issue, I would greatly use it, and thank yee.