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#631
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My circuit boards arrived today. They look fantastic. The fuzzy picture doesn't do them justice. Unfortunately I've been so busy with work that I haven't yet ordered the components to put on the boards.
For those who aren't up to speed, these boards are memory adapters. The EPROM chip that the ECU requires is obsolete. These will plug into the upgrade socket of the ECU and allow the use of modern EPROMs in place of the obsolete one. I am not planning to make batches of these to sell. But I will make a howto on ordering the bare boards and components, assembling them and programming new EPROMS. It should be easy for anyone who is technically minded and can work a soldering iron.
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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 |
#632
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On a separate note, I've been studying the USDM TCU a bit recently. I know I said I was going to finish the ECU first, but something we were discussing in another thread prompted me to look. Then I made a little discovery and I had to follow it up.
So far I've figured out that the duty cycles for Solenoids A,B and C are controlled by the timer output compare interrupts toc2, toc3 and toc4. I'll try and explain how it works. In the description below, I'm talking about milliseconds to make it easier to follow, but the units are not actually milliseconds. The actual unit is somewhat irrelevant, it's the percentage which is important. There are four things to consider: 1) A Timer (T) that is constantly running. It's just a number that increases by 1 every millisecond. 2) The Compare value (C). The ECU will interrupt what it is doing and run the solenoid switching code whenever T=C. 3) The wavelength (W) of 20000 milliseconds. This remains constant. 4) The Pulse Width (P) which starts out at 19000 milliseconds and is adjusted by the TCU depending on driving conditions. The operating range of P is from 1000 to 19000. When P=1000, P is 5% of W. In other words a 5% duty cycle. When P=19000, P is 95% of W, a 95% duty cycle. Initially, the TCU switches on the solenoid and sets C=P. In other words, it switches on the solenoid and says run the switching code after P milliseconds have elapsed. So, after 19000 milliseconds, T=C, the switching code runs. It turns off the solenoid and adds W-P to C. The solenoid has been on for 19000 milliseconds (95%), now it's going to be off for 20000-19000 = 1000 (5%). After 1000 milliseconds, T=C again, the switching code runs. It turns on the solenoid and adds P to C. This repeats over and over. Iteration 1, T=0 Set C=19000 Turn Solenoid on Iteration 2, T=19000 Set C=20000 Turn Solenoid off Iteration 3, T=20000 Set C=39000 Turn Solenoid on Iteration 4, T=39000 Set C=40000 Turn Solenoid off etc.. At present, there is no software to read the TCU through the select monitor interface. But if anyone wants to read and log the duty cycles of their A,B, & C solenoids then I can explain how to do it with the Hex Comm Tool. I am still working on figuring out how the TCU decides what the value of P should be at any particular moment for each of the solenoids. I found a great 6811 simulator program called "Wookie" which has a virtual oscilloscope function. You can actually change values in the software and view the resulting duty cycle.
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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 |
#633
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OK, if I'm reading this right, and I may not be, as my mind went a bit mushy through the calulations. But anywho, there MAY be coming a way to do a manual override of the TCU's active torque spilt?
This being the case, I'm looking forward to reading about this advance.
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[SIGPIC]http://www.subaru-svx.net/forum/image.php?type=sigpic&userid=5569&dateline=1207440 507[/SIGPIC] Naught but by the grace of God "42" Current Stable By Age:'89 Subaru XT6 Silver "Audrey" as in Hepburn '96 SVX LSi #767Brilliant Red "Lil Red" Now on the front burner. Looking for a totalled, but running parts car. |
#634
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Quote:
As for actually forcing these values to change, that would have to be done via a chip of some sort soldered onto the TCU. I don't believe it's possible to make real-time changes to the way the TCU operates as it is. You'd have to burn a chip that contains the modified code, then solder that chip onto the TCU board, and figure out how to switch the board over so it uses your chip instead of its onboard data. That is, unless Calum does for the TCU what he's doing for the ECU. |
#635
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I am not sure how many analog (voltage) inputs the TCU has. I know it has TPS Position, ATF Temp and Atmospheric Pressure. IF (and it's a big IF) there is another one that is unused then it might be possible to do some sort of DCCD-type arrangement. Where the torque split is set proportional to the voltage that you apply to a particular TCU pin. At present the TCU is "idiot proof", you can't damage the transmission by in normal operation. But adding a manual override would allow the driver to do dumb things like bind up the transmission and damage it. It might be better to keep the torque split active and just change the parameters that determine the calculated duty cycle. Quote:
I plan to try TCU mods soon.
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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 |
#636
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I'd be more than happy to be your USDM guinea pig again. Heaven knows it's been little but productive and beneficial!
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#637
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I'm interested in the transmission work. There's a fellow SVXer in sweden, I believe, working on XT6 cybrid steering, and paddle-shifting a 4eat. Both with external circuits.
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[SIGPIC]http://www.subaru-svx.net/forum/image.php?type=sigpic&userid=5569&dateline=1207440 507[/SIGPIC] Naught but by the grace of God "42" Current Stable By Age:'89 Subaru XT6 Silver "Audrey" as in Hepburn '96 SVX LSi #767Brilliant Red "Lil Red" Now on the front burner. Looking for a totalled, but running parts car. |
#638
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Paddle shifting could probably be implemented in software. I would use the wires for the power switch and the manual switch to indicate "change up" and "change down". You would leave the shifter in D and then replace the shift decision logic in the TCU software with some custom software. It might not even be very hard to do. But we don't yet have enough knowledge yet.
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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 |
#639
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Thanks Nomake. Did you ever get your USB cable working?
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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 |
#640
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I still haven't built the correction circuit but it works just fine for talking to the TCU without it.
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#641
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Quote:
I have tested it on my car and it seems to work. It should work on your car too because the ROM dump I'm looking at originated from your car.
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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 |
#642
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Awesome!!!! I'll play with this tomorrow, since it's my day off.
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#643
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Okay, I've got a problem again!!
Earlier, I was using the USB-Serial adapter along with you SSM adapter. Now, I'm using a USB-TTY adapter by itself. The Knoppix disc you gave me also had a bad sector (my own fault, it's scratched), so I'm using v5.1.1 of Knoppix instead. This appears to have caused a problem. With your original TCUScan, the program ends returning -4. I tracked that down to opening the driver to set options. I then changed the adapter to dev/tty and it returned a -2, something about invalid. So I changed it to dev/tty0 and it returned -1 "Permission Denied." Using any other number returned the same message. So apparently, my new adapter is either not being mapped by Knoppix or it's mapped to something different from my original USB-serial adapter. Help! How do I find out where this thing is mapped to? EDIT: I asked a Linux buddy of mine to help me out, and he found the problem; it's mapped to dev/ttyUSB0. Now I just gotta plug in and check it out! Last edited by Nomake Wan; 04-14-2008 at 12:27 AM. |
#644
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Quote:
Quote:
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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 |
#645
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Quote:
And now, the results! HOLY CRAP, MOST AWESOME PROGRAM EVER. You should've seen my grin as I drove around with the thing running. It's amazing how your programs seem to pull off what a certain other program can't--namely polling multiple variables all at once and returning accurate information 100% of the time in nearly real-time speed. Turns out, the only time I could get Solenoid C into 95% (FWD I'm guessing) was if I put the shifter into N or P. As soon as I put it into drive, I'd usually get about 60%-70%. Drop it into 1st and that lowers to 45% or so. I did manage to drop it to 5% once, when I mashed the gas from a dead stop. That was fun too. After the whole test drive was done, I did notice that a second percentage appeared next to Solenoid C's duty percentage. 27%. What's that about? Glitch? It didn't change at all after I messed around sitting in the driveway... hm. My only suggestion is that you add in an indicator for the Torque Converter Lockup. I'll test it the next time I hit the freeway. |
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