The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > Technical Q & A

Reply
 
Thread Tools Display Modes
  #1  
Old 07-05-2008, 05:53 PM
JLHollowX13's Avatar
JLHollowX13 JLHollowX13 is offline
Registered User
 
Join Date: Dec 2007
Location: Divide, Colorado
Posts: 341
Send a message via AIM to JLHollowX13
are ecu's interchangeable???

ok, here is my delima (sp? lol) i found a guy selling a fwd svx for 1k, (actually its 500 cash, 500 in trade) it has problems but would be a great parts car, or even dd if the title gets fixed (there is title problems so if they cant be resolved itll have to go to parts). it is a few hours from me though, and it doesnt have an ecu. my question is, can i use my ecu from my 92 in the 94? i would just need to use it to get it home and thats all. if it wont work, does anyone have a 94 ecu laying around that i could "borrow"? maybe send some $ your way as collatoral, then once it is returned i get a full or partial refund, depending on if you want money for using it. i kind of would rather just borrow one in a way because then i could take my svx to pick it up, but if that doesnt work i want to see if my ecu will work. thanks for any help!
__________________
1992 silver/black LSL - 142,xxx miles
power mode switch, ecu crush, intake silencer removal, ecutune, B&M transmission cooler
1971 toyota landcruiser - project.... someday
Reply With Quote
  #2  
Old 07-05-2008, 11:44 PM
lilbrudder lilbrudder is offline
i can make it on my oooowwwnn!
 
Join Date: Apr 2007
Location: las vegas
Posts: 237
Re: are ecu's interchangeable???

sorry jl, i can't answer you yes or no for the ecu swap but i'm running a 94 ecu in my 92 with no problem but they are both awd cars.
Reply With Quote
  #3  
Old 07-06-2008, 07:16 AM
SomethingElse's Avatar
SomethingElse SomethingElse is offline
word words wording
 
Join Date: Jun 2005
Location: CO
Posts: 1,387
Send a message via AIM to SomethingElse Send a message via MSN to SomethingElse
Re: are ecu's interchangeable???

Same here ran a 92 module in a 94. Pretty sure the only difference beetween the modules aside from the chips in them is the obd 1 and obd 2. A 95-97 module would be swapable and a 92-94.
__________________
Eric

Rebuilt P/S pump info... http://www.subaru-svx.net/forum/showthread.php?t=50918

If your car wont start info... http://www.subaru-svx.net/forum/show...ighlight=click
Reply With Quote
  #4  
Old 07-06-2008, 10:49 AM
TomsSVX's Avatar
TomsSVX TomsSVX is offline
Maniac modifier
 
Join Date: Dec 2003
Location: Branchburg, New Jersey
Posts: 15,489
Registered SVX Classic SVX
Re: are ecu's interchangeable???

yes the ECU's are interchangeable between any OBDI model 92-95. The only differences is the added EGR temp sensor on the later models. a 94 ECU will throw a CEL in a 92 considering there is not sensor there... but the 92 ECU will not in the 94

Tom
Reply With Quote
  #5  
Old 07-07-2008, 12:08 AM
JLHollowX13's Avatar
JLHollowX13 JLHollowX13 is offline
Registered User
 
Join Date: Dec 2007
Location: Divide, Colorado
Posts: 341
Send a message via AIM to JLHollowX13
Re: are ecu's interchangeable???

thanks tom on your info about the codes, thatll help me when i test drive it. with my 92 ecu i wont get confused if codes are thrown, ill know something really is up. the guy tells me that all it needs is the ecu, i guess ill see if i go and get it. the only thing is if i do get it and use it for parts, the car will have to be TOTALLY GONE by september, so ill post it up in the parts section if it comes to that. i guess ill see when i see the actual condition and if it REALLY only needs the ecu. thanks for all the help though!
__________________
1992 silver/black LSL - 142,xxx miles
power mode switch, ecu crush, intake silencer removal, ecutune, B&M transmission cooler
1971 toyota landcruiser - project.... someday
Reply With Quote
  #6  
Old 07-08-2008, 06:54 AM
b3lha's Avatar
b3lha b3lha is offline
Phil & Belha
 
Join Date: Aug 2001
Location: Alcyone Limited, Buckinghamshire UK
Posts: 2,671
Re: are ecu's interchangeable???

Quote:
Originally Posted by TomsSVX View Post
The only differences is the added EGR temp sensor on the later models. a 94 ECU will throw a CEL in a 92 considering there is not sensor there... but the 92 ECU will not in the 94
Tom
Have you actually tried this Tom?

I know the 92 ECU will detect whether there is an EGR temp sensor and switch into "california emissions mode" if there is, or remain in "standard emissions mode" if not.

You said previously that all the later models had EGR temp sensors and therefore all ran in "california emissions mode". But I assumed that the detection logic was still in the ECU and they would fall back to "standard mode" if no sensor was detected.

I can't help thinking that one mode or the other must have a couple of extra horsepower.
__________________
Subaru ECU and TCU Website
1992 Alcyone SVX Version L
1992 Alcyone SVX Version L
1994 Alcyone SVX S40-II
2004 Subaru Legacy 2.5 SE Sports Tourer
1996 Subaru Legacy 2.2 GX Wagon
1988 Subaru Justy J12 SL-II
Reply With Quote
  #7  
Old 07-08-2008, 07:59 AM
TomsSVX's Avatar
TomsSVX TomsSVX is offline
Maniac modifier
 
Join Date: Dec 2003
Location: Branchburg, New Jersey
Posts: 15,489
Registered SVX Classic SVX
Re: are ecu's interchangeable???

Quote:
Originally Posted by b3lha View Post
Have you actually tried this Tom?

I know the 92 ECU will detect whether there is an EGR temp sensor and switch into "california emissions mode" if there is, or remain in "standard emissions mode" if not.

You said previously that all the later models had EGR temp sensors and therefore all ran in "california emissions mode". But I assumed that the detection logic was still in the ECU and they would fall back to "standard mode" if no sensor was detected.

I can't help thinking that one mode or the other must have a couple of extra horsepower.

Absolutely true... I put a 94 ECU into my 92 a couple years ago and came up with the EGR Temp sensor code... Had to change it out to a 92 ECU The temp sensor doesn't change anything, it merely detect when the EGR is open/closed by detecting the heat. So there are no extra ponies laying up in there

Tom
Reply With Quote
  #8  
Old 07-08-2008, 09:37 AM
b3lha's Avatar
b3lha b3lha is offline
Phil & Belha
 
Join Date: Aug 2001
Location: Alcyone Limited, Buckinghamshire UK
Posts: 2,671
Re: are ecu's interchangeable???

Quote:
Originally Posted by TomsSVX View Post
Absolutely true... I put a 94 ECU into my 92 a couple years ago and came up with the EGR Temp sensor code... Had to change it out to a 92 ECU The temp sensor doesn't change anything, it merely detect when the EGR is open/closed by detecting the heat. So there are no extra ponies laying up in there

Tom
OK. Thanks Tom. That's more interesting info for me to research. I thought that the ECU "commanded" the EGR when to open/close rather than "detected" when it was open/closed.

I seem to remember that the 92 ECU, when operating in california mode, does some extra calculation in the section that processes the reading from the O2 sensors and also in the section that controls the AFR learning cycle. Could it be that the EGR system introduces some kind of error into the O2 sensor readings that must be compensated for?
__________________
Subaru ECU and TCU Website
1992 Alcyone SVX Version L
1992 Alcyone SVX Version L
1994 Alcyone SVX S40-II
2004 Subaru Legacy 2.5 SE Sports Tourer
1996 Subaru Legacy 2.2 GX Wagon
1988 Subaru Justy J12 SL-II
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 05:13 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122