5EAT TCU Reprogramming Research Test Fund

Update: TCU purchased! See post 16.

Inspired by the LSD test fund, I’m starting one on the TCU. This is an offshoot of the 5EAT "Mad Scientist" Idea & Test Thread http://legacygt.com/forums/showthread.php/5eat-mad-scientist-idea-test-133715p5.html.

Subaru’s TCU actively controls all aspects of the transmission, and thus if reprogrammed can speed up shifting and increase reliability/torque capacity. Subaru 4EAT TCU’s have been hacked before in the case of the SVX and adding paddle shifters in an Impreza RS. I’m going to attempt this with the 5eat, and document the process as much as possible.

To do any real work though, a “test” TCU is needed. Once this is obtained, I can work to pull the code out of it, disassemble the code, and figure out how the TCU is programmed over SSM. If successful, you as the end user will be able to flash your TCU just current you currently do your ECU.

A 2005 TCU has been located on ebay http://cgi.ebay.com/ebaymotors/Transmission-BCM-ECU-LEGACY-2005-05_W0QQitemZ250599326147QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item3a58e241c3 ,perfect to start work. If another can be located for less (pulled from a wreck or 6mt swap) please post it here.

The goal of this fund is to make a reasonable offer to the seller by April 23. I’ll be contributing to the “fund” as well, and any "over flow" funds will go toward the equipment required to pull the ROM.

PM me for paypal info. If for some reason the sale falls through or offers are rejected, a paypal refund will be issued.

The list of people who have contributed financially (THANK YOU!)

1) RIPjeep2002 - $20

2) ClimberD - $15

3) M Sprark - $30

4) KyLegacy 2.5GT - $15

5) sic GT - $10

6) DanT55 - $20

7) rubberman - $20

8) TMP - $25

Crap dude, my PayPal account is zero right now and I think a bank tranzaction takes 3-5 business days. That may be too late or cutting close. I'll try to do it today.

In the 5eat front LSD test fund thread, I paid for the diff to be shipped before I had received half of the donations. So no worries there. Important thing is the OP/tester gets his money eventually so the burden is not all on him

In the 5eat front LSD test fund thread, I paid for the diff to be shipped before I had received half of the donations. So no worries there. Important thing is the OP/tester gets his money eventually so the burden is not all on him

Agreed there.. I'll be dumping money into test equipment after I get the thing in, so any bit will help deaden the blow to my wallet.

Thanks for every one's help so far.

I've done a search on car-parts.com (list alot of junk yards) and there are a few on there if the ebay one falls though. It's harder to verify though as they dont have pics.

Would like to help out. PM sent.

Also, do you foresee any issues with the SI drive function?

Regards,

DT

I'm not sure, but I doubt it. There may be ways to make it work BETTER with Si-Drive, but that's not really in the scope I'm looking at right now.

From what can be gathered from the service manual and RomRader forums, Si-Drive just affects the throttle mapping. Thus the TCU isn't really responding differentially then if you just drove the i or S# throttle curves manually.

I'm not sure, but I doubt it. There may be ways to make it work BETTER with Si-Drive, but that's not really in the scope I'm looking at right now.

 

From what can be gathered from the service manual and RomRader forums, Si-Drive just affects the throttle mapping. Thus the TCU isn't really responding differentially then if you just drove the i or S# throttle curves manually.

I've also heard boost tables.

Money sent. Should be able to help more after I move.

Thanks, every little bit helps. The TCU is the first cost in this, I'm going to have to buy the tools to work with the chips inside it and maybe a few trips to the dealer. One advantage to this 2005 TCU is there is a software update out for it. So as a backup, I can set my laptop up to "sniff" the dealers tools used to reflash it.

Update: We now have a test TCU! With you all raising the money so fast (under 24 hours:wub:) I was able to go ahead and buy it this morning. Thank you again every one for the support, the fund covered all but $13 or so of the cost.

When the TCU gets here, I'll start a new thread on hacking it.

Thank you!!

woohoo. looking forward to seeing what you find or can do.

++

utc, I was out this week-end, if you are out any $ let me know and I'll cover.

And no, the Si drive is not a function of the TCU. However, there will be differences because the 05-06 did not have rev-matching on downshifting. Didn't it come with the 07-09? I may be wrong on the years but this is something we need to keep in mind. However, I am not sure, again, if this is a TCU function or ECU. I would think the ECU since it blips the gas.

Just got word via email, TCU has shipped!

Paypal sent. Really glad that utc_pyro is taking on this project! Keep us updated if you run into any roadblocks, there's a few EE's at my work site that I might be able to talk to if needed.

Thanks for the support. If I run into any issues I'll let every one know.

utc, I was out this week-end, if you are out any $ let me know and I'll cover.

And no, the Si drive is not a function of the TCU. However, there will be differences because the 05-06 did not have rev-matching on downshifting. Didn't it come with the 07-09? I may be wrong on the years but this is something we need to keep in mind. However, I am not sure, again, if this is a TCU function or ECU. I would think the ECU since it blips the gas.

I think I'm +$7 right now, so I dont really need any more dontations at the moment. First I need to figure out what tool(s) I need to pull and work on the ROM before I'll know what the total project cost will be. If the processor is supported by IDA 4.9 then the wont be too much. If I need to buy IDA 5.x Pro, then it's going to cost $600+ .

Also, I think the throttle blipping is a function of the BIU+ECU based on the SSM and service manual info I've been reading. When you push the "shift" buttons the BIU sends out commands to the ECU and TCU via the CAN bus to shift. I'm not sure if any additional info is transmitted by the TCU to the ECU about how much to blip it though. We'll have to pull the ROM on the BIU at some point as well to tell.

The first thing I'm going to focus on is how to read/flash the TCU's rom via SSM (how you do your ECU now). After I get that figured out, we should be able to pull a 07+ TCU ROM with an OpenPort 2.0 and compare.