Jump to content
Ultimate Subaru Message Board

95' Legacy mod to accept 97-99' ej25d ecm?


Recommended Posts

**This is a carry-over from another thread and needed an actual dedicated thread to get answers. Was talking about ecm swaps from an ej25d into ej22 Legacy for a possible bump in the tune i.e. advanced timing and higher redline, etc.**

 

 

 

I wouldn't repin the (ej25d) unit itself as I suspect the pins are soldered directly to the printed circuit board. If the pins were connected via ribbon wire, then it'd be possible to reassign the pins that way. Otherwise I'd try and make an adapter from the donor's harness and probably snag the pinout section from another 95' ecm and make an extension adapter that'd be straight up plug and play, but not interested in a cel being on constantly. I'm still confused though, my 95' ej22 has egr from what I can tell, so what's the issue exactly with the newer ecm's with mine other than the pinout being different? For $20 an ecm plus another $5 at most for the harness, I'd be willing to at least try if it's possible?

 

 

 

Also, what controls the shift points? Would it be possible to swap in another unit that controls the trans from something that was intended to be "sporty" when marketed? Like say an SVX?

Link to comment
Share on other sites

No need to repin.

The 95 ej22 is compatible with ej25d ecu's from 96-98. I "assume" the 96 was omitted because its map is slightly different as it was the first year of the EJDOHC which ran on premium fuel. I have not heard of any people who have swapped and find that mpg is an issue. In fact I have a 96 swapped OB and it gets 25 mpg highway.

You will get the higher rev limit no matter what.

 

O.

Link to comment
Share on other sites

No need to repin.

The 95 ej22 is compatible with ej25d ecu's from 96-98. I "assume" the 96 was omitted because its map is slightly different as it was the first year of the EJDOHC which ran on premium fuel. I have not heard of any people who have swapped and find that mpg is an issue. In fact I have a 96 swapped OB and it gets 25 mpg highway.

You will get the higher rev limit no matter what.

 

O.

 

What year is your Legacy? Can't tell if your Legacy is 96' or the ecm is a 96'?

Link to comment
Share on other sites

I had a real nice post typed up and my damn phone lost it. So here's a quick and dirty version.

 

95 is a one year ecu, the pinout is different from 96-99. You can't change the pin locations inside the ecu because they're soldered to specific circuits on the ecu motherboard. The only way to do it is to change the pin locations on the body side connection. Basically grab a pinout for the 95, and one for the 96-99 and make yours match the newer one.

 

Shift points are controlled by the tcu, there isn't a performance tcu available for our cars. But there is a mod that will put you into "power mode", something the non-us market 4eats had that we didn't get. You can read more on this in this link.

http://sl-i.net/FORUM/viewtopic.php?f=70&t=17483

Link to comment
Share on other sites

I already tried grounding that pin for the trans unit awhile back. At first, I thought it made a difference, but further experimenting yielded no difference with it grounded or not, and shift points seemed to remain the same. Would a heavier vehicle with a ej25 or an early ez have a better trans map?

 

 

My 95' does have an EGR valve, transducer, and solenoid, so what exactly are you referring to with the EGR system as it's clearly sitting there right by the brake booster at the back of the driver-side intake manifold? 

 

EDIT: Maybe I have a late 95' with a 96' drivetrain?

Edited by Bushwick
Link to comment
Share on other sites

I never tried the power mode mod on my 97, I swapped it to a manual about a year ago. So I was just going off others input on that. That's my only personal advice for the shift points on the automatic, however I do vaguely remember some old posts about a diy shift kit aimed at svx 4eats, which are basically identical to legacy 4eats except for the final drive ratios. So maybe some searching can get you results on that subject.

 

And the egr cel warning was for capn_r who posted right above me, sorry for the confusion there.

Link to comment
Share on other sites

OK, so the EGR isn't an issue. Assuming I can get the ecm pins to match my body-side harness, I can then try a more favorable year then.

 

Do you happen to have or can you link a 95' ecm pinout and say a 98'-99' pinout? The Legacy Outback are extremely common around here in those years should this will be a fun project. Already run premium anyways and with 93 dropping to 2.39 a gallon, I won't mind ;) 

Link to comment
Share on other sites

Thanks Bratman. I didn't realize the info was that readily available. 

 

Can anyone confirm if 97', 98', or 99' ej25d would be better than the other (even marginally)? I'm assuming they all have the rev limit bump as well? It'll be a little bit of work to try this so wanna go with the best option the first time. Also, has anyone ever tried to dyno a before/after? Obviously peak hp might be a few more due to the higher rev limit assuming the cams aren't running out of steam. Very curious on the timing advance increases. Thanks again!

Edited by Bushwick
Link to comment
Share on other sites

To my knowledge there is very little, if any difference in the tuning for any of those years. All three years were rated for the same hp and torque figures so it would stand to reason they would be the same. There were differences in the evap systems for 95-97 and 98/99, but that's a non-issue as far as the ecu is concerned.

Link to comment
Share on other sites

And one more thing, I noticed the pins are numbered in some images. Is it safe to say pin #1 in a 95' would be the same as a pin #1 in a 97'? With just pin #1 being in a different location? Or would I have to look at each function and go off that? It'd obviously be way easier rerouting if the numbers represent the same pins/functions, just in different locations.

Link to comment
Share on other sites

I looked all this up a couple years ago and I seems to remember 95-97 being the same, and 98-99 being the same based on the pinouts.

 

If you want to download all the servic manuals, all you need to look at is the ECU I/O charts to determine if ECUs have compatible pinout.

Link to comment
Share on other sites

No need to repin.

The 95 ej22 is compatible with ej25d ecu's from 96-98. I "assume" the 96 was omitted because its map is slightly different as it was the first year of the EJDOHC which ran on premium fuel. I have not heard of any people who have swapped and find that mpg is an issue. In fact I have a 96 swapped OB and it gets 25 mpg highway.

You will get the higher rev limit no matter what.

 

O.

 

95 ECU is different

 

The difference just a the evap system is whether the charcoal canister is at the front of the car or at the rear of the car.

 

Also IIRC early the MAP sensor is switched between Mani and Atmosphere where late model is switched between Mani and Vent line.

Link to comment
Share on other sites

^Thanks.  

 

I'm skimming the actual pins now to have label/color-coded references as they seem scattered throughout the 144 pages. Thankfully year by year changes are minimal i.e. page 32 on 95' Legacy is the same info for page 32 on a 97', with exception being where some wires are going on the actual ecm although the wires in the schematic are apparently the same. According to both .pdf files, (95' & 97') the actual plug connector for the ecm (B84) is physically identical between 95' and 99', even down to the same keyed slots. However, 95' thru 97' appears identical with the actual pins being used slightly different, whereas 99' has more added to the circuitry, so I'm focusing on 95' and 97' Legacy pinouts. I'll update with an abridged version in case someone wants it in the future. 

Link to comment
Share on other sites

95 ECU is different

 

 

Also IIRC early the MAP sensor is switched between Mani and Atmosphere where late model is switched between Mani and Vent line.

 

 

Do you know which year the MAP sensor changed connections? I'll try and look more closely at the circuit while skimming for pinouts to (B84). Although I don't remember seeing any vacuum lines left open to atmosphere when replaced recently. They either connected at the manifold or another port and terminated at sensors or valves.

Link to comment
Share on other sites

Do you know which year the MAP sensor changed connections? I'll try and look more closely at the circuit while skimming for pinouts to (B84). Although I don't remember seeing any vacuum lines left open to atmosphere when replaced recently. They either connected at the manifold or another port and terminated at sensors or valves.

 

It's actually a slightly diferent switching valve.

 

THe one that opens to Atmo has a small filter head on it.....whereas the one that switches to a T in the canister line has a nipple there instead of the Filter head.

 

Might be 97 that the change came???

 

95 is definately a one year only arrangement.  (connector is the same, just some circuits moved around within it and some wire colors changed) 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...