ECU Interchangeability

[mountaingoatgruff]

i need to know about the interchangeability of spfi ea82 ecu's from late 80's to early 90's. i've been looking and have come across some black ecu's that claim to be from 88/89/90 and even newer cars, many silver ones from 91-93 and a gold one from an 88 (i don't think the ad is correct - it doesn't look like my spfi ecu). what years are interchangeable for the ea82 spfi system ecu's(specifically a 92 ea82 spfi), and which models/years are interchangeable between auto and manual cars? i'm looking at buying a black ecu from a guy that says he pulled it from a 91 car with an auto trans and he insists the same year manual car ecu's are the exact same. is this true?

[idosubaru]

which models/years are interchangeable between auto and manual cars? i'm looking at buying a black ecu from a guy that says he pulled it from a 91 car with an auto trans and he insists the same year manual car ecu's are the exact same. is this true?

XT's are always interchangeable from auto to manual, i imagine many EA82's would be as well.

 

the 3AT (3 speed automatics) may differ though, but i would bet they're still the same as the manual.

 

there's was one year in the mix that was a real goof ball...can't recall if that was EA81 or EA82 though, hopefully someone will pipe up - i think GD knows a lot about that.

[GeneralDisorder]

XT's were never SPFI.

 

Exactly how many times do I have to go over this??

 

You can interchange any of them - all the SPFI systems used a similar enough pinout to run the vehicle. The differences lie only in the transmission type and the types of clutch/neutral/park switches that it understands.

 

Black ECU's were not used after 90.... maybe 91. The silver ECU's have the added clutch switch in addition to the neutral switch - that is the ONLY difference between the manual versions. Automatic versions are the same regardless of black/silver.

 

The gold one is probably a feedback carburetor ECU for a CA 4WD, or a CA/49 states 2WD EA81 Hatchback. Not applicable to your setup at all. Either that or it's some turbo/XT MPFI ECU. Either way it doesn't apply to you.

 

I don't know if I can break it down any more monosyllabically than that. I've given you this information at least three or more times in your conversion thread. It's got to be up to you now to comprehend it.

 

GD

[azsubaru]

I have a 91 Loyale, manual, 2WD, SPFI.

 

I replaced the original silver ECU with a black one about 6 months ago. As GD says, there has been NO noticable difference in performance and NO unexpected codes thrown.

[mountaingoatgruff]

wow GD, you are an rump roast! forgive me if i am hesitant to take your word as gospel when i receive conflicting info from mutiple sources. its been my experience with mopars that those who are revered for their automotive knowledge are usually reliable but never to be taken as prophets. i'm not looking for monosyllabic information, just additional perspectives/opinions to verify that information or let me know i need to investigate the conflicting info i receive elsewhere.

[idosubaru]

i receive conflicting info from mutiple sources.

can you post links to those conflicting sources? that GD gives such specific information should give some confidence in the actual differences and not just information that is being "guessed at" or regurgitated. if you can post links of conflicting stuff maybe we can figure out what is confusing about it and why. specifically addressing the conflicting info is much easier than trying to nail down a decade of interchangeability.

 

be thankful that GD donates his time here....the asses are the knowledgeable folks out there that are not willing to help.

[mountaingoatgruff]

i can't post links because not all of my information comes from the internet.

 

the local parts store has a guy that my father and i have both gone to for parts for years. he has a whole wall of shelf after shelf of parts listing books/catalogs. i've gone to him for things that kragen's, dealerships and junkyards all laugh at me for asking about and he's hardly ever gotten inaccurate information from his books or failed to deliver.

 

i asked him to help me find an ecu for my application (of course i explained exactly what my application is) and he told me he has a supplier with parts available that say "1990-93 Subaru Engine Computer 22611 AA392" - we called the supplier to verify if its a black or silver unit and its black. (my silver 92's part# is 22611 AA395.)

 

according to GD, subaru changed from black ecu's to silver ones in 90 or 91 so why would this black ecu's part listing say its for cars up to 93?

 

also there's many listings on ebay with all sorts of item descriptions. of course, that's ebay so we all know that most of the sellers likely aren't doing their research before writing their item descriptions, but i've contacted a couple that insist they pulled their listed ecu from a particular vehicle with their own hands. one's description matches GD's info and the other doesn't.

 

in situations like this what i usually do is attempt to gather as many opinions as i can (and short of documentation from subaru or an affiliated company - ALL of this is observation based opinion at best) so that hopefully a consensus will emerge that i can use to make an educated guess.

 

just because i'm asking this question again in a separate new thread does not mean i am a moron that can't understand what GD has already said. it means i have decided not to guide this purchase entirely by the opinion of one man that i don't know, which would be something that would make me a moron.

 

one other thing, too - Gloyale stated in a post to my spfi ?'s thread "My 87 FSM shows a clutch switch and neutral switch? 88-89 do not? For Automatics, 87 uses the same neutral and p(Clutch) signals. But in 88+ additionally has In gear signal?"

 

were these questions answered somewhere that i missed, particularly the one asking about the fact that his 87 fsm shows a neutral AND a clutch switch? if Gloyale was right and his 87 fsm shows a neutral AND clutch switch it would seem that the only documentation from an authoritative source provided so far conflicts with GD's information.

[idosubaru]

Subaru ECU's are jacked up. parts numbers all over the place and some interchangeable/some are not. all the XT's i've worked on are always gold and some interchangeable, some are not. never seen a silver or black one.

 

is it that hard to find one or are you trying to locate a really cheap one?

 

have you tried posting your exact make and model on the parts wanted forum, someone may have one for you. unless you've heard otherwise i would worry the least about the auto verses manual thing, but that's only based on unrelated XT experience, they are all interchangeable with no issues at all. i realize that's not SPFI but it wouldn't surprise me if SPFI's were the same in that regard.

[mountaingoatgruff]

to explain for grossgary -

 

i'm doing an spfi conversion on my 84 hatch. because i'm in california, i'm worried about whether or not my car will pass smog checks.cali doesn't really allow these kinds of mods but if the smog tester doesn't notice and the car passes, the mod gets overlooked.

 

if my check engine light is on i automatically fail, no ?'s asked. in order to prevent this, i need an ecu which requires input that i'll be able to give it.

 

besides, i don't want my cel on every time i drive my car anyhow - i could miss a cheap opportunity to fix a potentially expensive problem or something like that and my wife would never trust it enough to drive it.

 

i can't feed it a signal from an auto tranny's park switch because i have a 4speed so using an auto car's ecu will likely fail me come smog time. i can't use a later silver ecu because (according to my understanding so far) they require a neutral switch input and a clutch switch input.

 

my car doesn't have either switch. i can rig the neutral switch by using a switch mounted to the clutch pedal but after i rig the neutral switch this way i have no place to put the clutch switch.

 

because the earlier black manual car ecu's (again, according to my understanding so far) don't require both inputs, only the neutral switch input, i need one of these ecu's for my car.

 

i've found a few black ecu's, but the sellers either say they are for years that don't correspond to the info i have received here or they don't know if they're from auto or manual cars. they're just too expensive to buy one and see what happens ($80+ is all i can find).

 

all this adds up to mean i need to figure out what my car really requires and what applications these ecu's i've found will work with - without tripping the check engine light for lack of input from whatever source.

[idosubaru]

ah ha, a conversion.

 

cali doesn't really allow these kinds of mods but if the smog tester doesn't notice and the car passes, the mod gets overlooked.

same in most states...like maryland. "technically" motor swaps are illegal...but everyone does it. just know your emissions laws, pass them and move on.

 

if my check engine light is on i automatically fail, no ?'s asked

same thing in maryland and many other states, you can't even have it tested with the light on. with newer cars you can't even clear it and have it tested until it runs through a certain number of cycles.

 

of course i do realize ca. is more quirky with their smog testing. good luck with the conversion.

[mikeshoup]

I like Colorado. They no longer fail emissions for a CEL.

[mountaingoatgruff]

yeah, ca sucks, and its only getting worse. my brother live in sc and co and i'm sure you'd love to hear the kinda crap they give me for not having moved out of ca already. i planned on moving to wa in less than two years, but lately i've considered co because i have closer family there.

 

about the ecu's:

 

i called vintage subaru in nc and as soon as i got off the phone i kicked myself twice. i've dealt with them before and kept thinking every now and then that i should call them.

 

the gentleman there told me he has part number listings telling which computers correspond to which model/option cars. he assured me that he would be able to find me the correct 87-89 black ecu for a 4wd manual car AND he beat the best price i've had so far for a "guess-which-one" ecu by $20.

 

he'll have an update for me monday and if all is well this beast can be laid to rest and it'll be on to the next...

[ivantruckman]

"monosyllabically " ???????????????????

[GeneralDisorder]

I've parted many cars, and purchased many ECU's from my junk yards (my yards have dozens at all times) and I have yet to see a black ECU in a post-'90 vehicle. Talking SPFI Loyale's and GL's only here - not turbo's, MPFI XT's, or any of that.

 

It's possible to find one of course, but it's a swap if you do. The ECU's are rugged, but if you hookup the battery backwards they will blow in about 30 seconds. This has surely led to a few being swapped with different years.

 

Across the board the black ECU's don't have the neutral switch and the silver one's do. I challenge anyone here to systematically prove this to be inaccurate.

 

Parts books and eBay auctions listed by people that can't even remember what type of transmission it came from are hardly to be trusted. It's difficult to find parts books that are RIGHT on Subaru stuff - that's why most of us use the dearship now.

 

If you want part numbers - go to the dealer and find someone in parts that actually has a brain.

 

GD