5EAT TCU Reverse Engineering

[utc_pyro]

05-06 no upshift, no rev-match

07-09 upshifts, rev-matches

07-09 had revised mechanicals and TCU reflash. At the very least the valve body is somewhat different.

 

Technically it's a whole new TCU. It's based on a newer chip the same as the ECU.

[TSiWRX]

I'll be Cole Trickle. You be Rowdy.

 

Deal.

 

Cue Apollo Smile's "Thunder Box."

 

BRING IT!

[m sprank]

"Rubbin is racin".

 

"Remember me?"

[fishbone]

check your transmission fluid right behind your engine on the left side(driver) Its down in the bay a bit and my arm was always getting cut up(before I took off the engine cover and put it up in my garage). As for the tranny cooler mod, I don't remember where or who said it, but it was in multiple places when I was looking at it. I actually did it when I was stage 1. Its really easy to put in too.

The dipstick on the left side, as you are facing the car, is the front differential fluid. The dipstick is short, yellow and right on the tranny.

The tranny fluid dipstick is on the right of the engine, somewhat close to the intercooler, a little under it. IIRC the cap is orange? Can't miss it. Quite a bit longer too.

 

My experience with a tranny cooler is it made no difference in the winter, I have a TruCool with the bypass feature. I know this because torque lock-up and 5th gear upshift happened just about the same as before I got the cooler installed. For those that don't know, the tranny won't lock up the torque converter and, sometimes, not engage 5th until the ATF is up to temperature. An overcooling would tell me the above would take longer to happen.

[seabass07]

Where did you get the transmission cooler?

[fishbone]

Transmissioncoolers.us

 

TruCool 4452

[fishbone]

Try this. Jab the gas pedal. Just give it a quick jab. Like stab it. From steady throttle lift off, jab it 50% real quick like you would clutch in a spirited shift on a MT. The tranny should downshift from 5th. At least mine does, without fail. It usually throws it in 3rd and will hold that gear for a good bit waiting for input.

Expanding on this idea, I just got back from a drive to Subway and I took the long way, heh.

I don't know if this is normal of all auto trannies, forgive me but this is only the 2nd automatic I have owned in a long line of MT cars, if you do a jab, release and floor the pedal within a second, the tranny will downshift at least 2 gears and you'll take off. Flooring it from a steady pedal in top gear will not always result a proper downshift, especially if you are cruising in 4th at around 45. I have had it before hold 4th gear (WTF). Sure enough I tried this in 4th and 5th at cruising speed, jab-release-floor it and yep, kicked it down right to 3rd or 2nd.

Also, with all this talk about the 5EAT failing from the top down, I floored it in 4th as soon as the tranny allowed me to upshift it, did the same in 5th. Torque converter let it slip up to around 3500 and held the revs solid there as the car gained speed.

I agree, it does kinda shift like ass from 4th to 5th at around 35 if the tranny is in 4th and you are accelerating to catch up with traffic. The way it does it for me the revs just stay steady and when she shift happens, I don't even feel it, I just see the needle jerk up-down 50-80rpms and the gear is engaged.

So maybe it's not always the clutches that fail, but the bands too, or primarily those.

[RIPjeep2002]

I believe it is a combination of both the gears and bands that let go due to the heat caused by the added stressed of WOT shifting at stg2+.

[seabass07]

I wonder if it the input clutch is the culprit. I think it is a shared clutch between 4th and 5th and I think it may take the brunt of the shift shock. I think it is the only clutch in there that is fully engaged in both gears that wouldn't effect any other gears.

[fishbone]

And I get a fail for posting in the wrong thread! It's a moot point moving my reply at this point.

[seabass07]

LOL! I failed to for replying and not noticing.

[underground000]

I believe it is a combination of both the gears and bands that let go due to the heat caused by the added stressed of WOT shifting at stg2+.

 

I took a look at the 08 transmission and theres no bands just pistons/clutches. The brakes are also piston/clutches

 

Input Clutch

Direct Clutch

Reverse Brake

Forward Brake

Low Coast Brake

 

What happens is the Brakes let go and the brakes restricts reverse rotation of sun gear or lock sun gear

 

I have some understanding of auto trans, I took them completely apart and put them back together before

Edited November 6, 2010 by underground000

[seabass07]

The input clutch connects the input shaft gear assembly to the rear assembly (output shaft) when engaging 4th and 5th. It doesn't appear that the actual gears are failing, just the clutches. It must be a bit weak for extra power. Maybe that is the clutch assembly that some people are adding clutch disks to.

[underground000]

The input clutch connects the input shaft gear assembly to the rear assembly (output shaft) when engaging 4th and 5th. It doesn't appear that the actual gears are failing, just the clutches. It must be a bit weak for extra power. Maybe that is the clutch assembly that some people are adding clutch disks to.

 

correct people add clutches to the clutch assemblies to hold more power.

 

Dont know if they make it for Subaru's but theres a company that makes a clutch/steel on 1 piece of steel (if that makes sense) So one side is a clutch and the other side is a steel. This way you can pack almost twice as many clutches/steels in the assembly. Normally its clutch stacked next to a steel

 

Something like this

http://www.britcycle.com/products/images/571362D001.jpg

 

Vs normal type

http://www.ahpminis.com/store/images/0404.JPG

Edited November 6, 2010 by underground000

[seabass07]

I know someone here had this done when they had an IPT VB installed. Apparently there was room for 2 more disks...I think.

[seabass07]

It also looks like all gears have 3 separate clutch assemblies engaged when in gear except for 5th gear which has only 2. One of those is shared with 4th. So 5th could easily take out 4th.

[lieutenantcolumbo]

I know someone here had this done when they had an IPT VB installed. Apparently there was room for 2 more disks...I think.

 

They put in extra clutches for my 4th & 5th gears when they installed my TransGo kit. I believe they had to remove some material from the case to allow them to both fit, and they said there wasn't room for anymore than the two extra clutches.

[OGHK87Jay]

They put in extra clutches for my 4th & 5th gears when they installed my TransGo kit. I believe they had to remove some material from the case to allow them to both fit, and they said there wasn't room for anymore than the two extra clutches.

 

Out of curiousity how much did it cost to to rebuild your whole tranny with all them goodies added to it minus the transgo?

[fishbone]

Oh, what have I started Mechanical discussion in an electrical/programatic thread

utc_pyro, have you looked at the open source FreeSSM yet? It connects and communicates straight with the TCU IIRC. I haven't tried it yet but it reads codes, resets the learned logic, etc. Maybe the developer may be able to tell you a thing or two?

http://developer.berlios.de/projects/freessm/

[LGTONCOKE]

I tried connect using freessm it wouldn't let me idk if it is cause I was using a tactrix cable or what.

 

EDIT: after going back through the pages and re reading some stuff I see the Tactrix cable doesn't work. I was wondering if someone could just confirm that this is the cable I need..

 

http://www.alpha-bid.com/vagusb.html

Edited November 7, 2010 by LGTONCOKE

[lieutenantcolumbo]

Out of curiousity how much did it cost to to rebuild your whole tranny with all them goodies added to it minus the transgo?

 

Response posted in 5EAT Pride! thread.

[KyLegacy 2.5GT]

Just wanted to let everybody know that I edited the requested torque table and throttle plate position table within RomRaider and I felt a pretty good difference in shifting yesterday and today. I multiplied the values in the requested torque table by 1.4 or 40% and did the same with the top row of the throttle plate table. I did this because I was going autocrossing today and just wanted a little more security while racing the car.

 

Reviews:

After driving around for a while and the ECU had relearned all of its parameters, I went out for a spirited run. The transmission shifts a lot more precise in all modes..... but only when you are getting into the gas... If you are driving around town, it may feel a little different, but not much. I could really feel the difference in Sport Auto and Sport Manual (I don't ever drive in D). Sport Auto still likes to slip the gears and there is still a huge lag between shifts when using Sport Manual..... But when the gear engages it feel really strong!!!! Not that sloppy crap we are used to. I had 6 laps on the course today and the shifts were strong the whole time (I just can't get used to the delay after you hit +, the tranny shifts when it wants to). Even on the way home after all of that racing, the shifts felt really good.

 

I highly recommend doing this on your tunes if you have a Vag-Com or Tactrix cable!!! It not going to chirp your tires or really throw your head back, but it will take out a lot of slop (and hold more powa!). See the attached screen shot below.

[hadvw]

Just wanted to let everybody know that I edited the requested torque table and throttle plate position table within RomRaider and I felt a pretty good difference in shifting yesterday and today. I multiplied the values in the requested torque table by 1.4 or 40% and did the same with the top row of the throttle plate table. I did this because I was going autocrossing today and just wanted a little more security while racing the car.

 

Reviews:

After driving around for a while and the ECU had relearned all of its parameters, I went out for a spirited run. The transmission shifts a lot more precise in all modes..... but only when you are getting into the gas... If you are driving around town, it may feel a little different, but not much. I could really feel the difference in Sport Auto and Sport Manual (I don't ever drive in D).

 

 

Anyone know if I could do this with my APv1? Can the Street Tuner software do it? Then again, I got ProTuned - can Street Tuner read ProTuner files? Can the v1 Street Tuner software still be found anywhere?

[LGTONCOKE]

Just wanted to let everybody know that I edited the requested torque table and throttle plate position table within RomRaider and I felt a pretty good difference in shifting yesterday and today. I multiplied the values in the requested torque table by 1.4 or 40% and did the same with the top row of the throttle plate table. I did this because I was going autocrossing today and just wanted a little more security while racing the car.

 

Reviews:

After driving around for a while and the ECU had relearned all of its parameters, I went out for a spirited run. The transmission shifts a lot more precise in all modes..... but only when you are getting into the gas... If you are driving around town, it may feel a little different, but not much. I could really feel the difference in Sport Auto and Sport Manual (I don't ever drive in D). Sport Auto still likes to slip the gears and there is still a huge lag between shifts when using Sport Manual..... But when the gear engages it feel really strong!!!! Not that sloppy crap we are used to. I had 6 laps on the course today and the shifts were strong the whole time (I just can't get used to the delay after you hit +, the tranny shifts when it wants to). Even on the way home after all of that racing, the shifts felt really good.

 

I highly recommend doing this on your tunes if you have a Vag-Com or Tactrix cable!!! It not going to chirp your tires or really throw your head back, but it will take out a lot of slop (and hold more powa!). See the attached screen shot below.

 

 

Now for the throttle plate when you say top row, are you talking 800rpm straight across?

[fishbone]

Thanks for the input KYLegacy. I am going to try it out.

OK, I have Access Tuner Race. 05 LGT so I only see Requested Torque table and Throttle Maps, no Si Drive crap.

Here's what I got. Help me out please.

Edited November 8, 2010 by fishbone