Welcome to the North American Subaru Impreza Owners Club Sunday December 8, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning > AccessPort

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 06-25-2019, 11:57 AM   #1
Louisvillewagonmafia
Scooby Newbie
 
Member#: 348886
Join Date: Mar 2013
Chapter/Region: MWSOC
Location: Louisville, KY
Vehicle:
2004 Subaru FXT
Red

Question Replacing ECU ID in 04 FXT and running as 04 STI with AP

Hello all.

Currently working on a 2004 USDM FXT build. The specs are not particularly important to this discussion, but the rough cut is an HTA 86, PPG trans, and a closed deck stroker.

I am excited to try out the flex fuel tuning features and really wanted to utilize custom sensor logging via Accessport.

I previously tuned the 04 FXT ECU open source, and modified the electronic ECU ID by flashing a 2004 STI ROM to the 2004 FXT ECU to get easier access to previously identified definitions for some tricky tables and logging parameters.

When switching to accessport, i realized that the current 2019 revision of accesstuner does not enable these features on the 2004 FXT platform (CCF, including custom sensor logging, flex fuel, and others). I was disappointed, as the reason i switched to COBB was for the simplicity of not having to reinvent the wheel or install odd workarounds in OS every time i hit an undefined area or wanted greater ease of functionality. COBB is just easier, in so many ways.

I contacted COBB about my scenario, and Bill informed me (thanks Bill!) that it is unlikely that the 04 FXT will receive these features at any point (though the 05 FXT and 04 STI have them enabled)- and of course mentioned the path that some have taken- swapping the 04 STI ECU into the 04 FXT (as they are plug and play), then treating the car as an STI from the AP perspective and moving forward. To note, this is an unsupported path and was not suggested by COBB, only noted that this is what some have done, and i was warned sincerely to be careful regardless.

I purchased a used 04 STI ECU to set aside in case i completely ruin this FXT one, but decided to move forward by keeping my re-imaged FXT ECU and installing the 04 STI accessport software into my electronically swapped environment to see what happens. If it works without a hitch all the way to tuning out my HTA86 in SD, then this could potentially open a door for other 04 FXT owners to access otherwise unavailable COBB features.

The 04 FXT ECU, which thinks it is an 04 STI ECU, now has the 04 STI accessport installed with COBB custom features activated. There were no errors during install, and so far it appears to be reacting appropriately to my inputs in Accesstuner.

I am in no way suggesting that anyone else do this! I have an extra ECU handy and am performing this testing on an engine that i plan to throw in the trash in short order in favor of my new built swap, so all potentially affected parts will be cycled out anyway, or can be.

My question is, has anyone else tried this method instead of a full ECU swap? If so, did any quirks or problems come up throughout the process that i should watch out for? Does anyone have any notes to mention regarding actual physical or memory differences between the two ECU's that might potentially leave me stranded when trying to enable certain features or actions?

Best case, id like to test and figure out the quirks while my engine is a throwaway, then transition to the new engine with confidence that my ECU is reacting appropriately everywhere that matters.

In open source, the FXT ECU has no problems running STI roms, as the 32-bit base is the same, definitions and addresses are just different. Memory size between FXT and STI roms typically reads within bytes of one another, and all pinouts match physically on the ECU. Just trying to get ahead of anything that might come up, unless i'm the lone wolf trying this out...

thoughts anyone?

thanks
* Registered users of the site do not see these ads.

Last edited by Louisvillewagonmafia; 06-25-2019 at 12:23 PM. Reason: corrected title
Louisvillewagonmafia is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 10-06-2019, 02:46 PM   #2
gymhobo
Scooby Newbie
 
Member#: 332848
Join Date: Sep 2012
Chapter/Region: MWSOC
Location: Des Moines, IA
Vehicle:
2004 Forester XT 5MT
Red

Default

Hello, I also have a 2004 FXT and would like to go to flex fuel tuning. I have been tuning using Cobb's software, but was sad to see the CCF only supported 2005 fxt ecus.

How has this been working out for you? I suppose I would have to get a hold of a tatrix box to temporarily go back to romraider to flash a 2004 sti rom to my fxt.

Interested in selling off your 2004 sti ecu?
Thanks
gymhobo is offline   Reply With Quote
Old 10-07-2019, 10:26 AM   #3
Louisvillewagonmafia
Scooby Newbie
 
Member#: 348886
Join Date: Mar 2013
Chapter/Region: MWSOC
Location: Louisville, KY
Vehicle:
2004 Subaru FXT
Red

Default

No issues yet, the car seems to respond to everything just fine in MAF mode, but i haven't leveraged the full suite of the CCF quite yet, the cold months are coming now, so the tear down to swap the monster engine from the stand into the bay is about to happen. I have no current issues though, so far i would say it is a success. I am still keeping my extra ECU for now though, just in case.
Louisvillewagonmafia is offline   Reply With Quote
Old 12-03-2019, 12:42 AM   #4
GreatOdinsBeard
Scooby Newbie
 
Member#: 490577
Join Date: Aug 2018
Location: Iowa
Vehicle:
2004 Impreza WRX
JBP

Default Update?

Any issues so far? I have an 05 FXT (Auto) and lots of spare STI bits (harness, Ecu, Intake manifold, and assortment of other stuff). I know the auto might be a non starter, but if not it could be a mock STI of sorts, right?
Thanks!
GreatOdinsBeard is offline   Reply With Quote
Old 12-03-2019, 09:25 AM   #5
Louisvillewagonmafia
Scooby Newbie
 
Member#: 348886
Join Date: Mar 2013
Chapter/Region: MWSOC
Location: Louisville, KY
Vehicle:
2004 Subaru FXT
Red

Default

This serves little purpose on a 2005 FXT. you have access to CCF already when using COBB. This is specifically useful for custom builds on a 2004 FXT only, where CCF is otherwise unavailable without swapping ECU's.
Louisvillewagonmafia is offline   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 -4. The time now is 03:34 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.