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#571
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Economy Switch Function on UK/Euro TCU
Joe (SVXistentialist) has kindly lent me a UK TCU. I have extracted the code with a view to finding out what the "Economy Mode" button does on the European cars.
It turns out that Joe was exactly right when he hypothesised that the Economy switch locks out power mode. With the Economy switch on, power mode will not engage when you floor the throttle. This seems pointless to me. If I floor the throttle it's because I want some speed and I want it now. So I decided to have a go at changing the program to make this switch a little more useful - like the power switch on JDM cars. Here is the part of the program that decides whether to use normal or power mode on a UK TCU: Code:
e5f7 12 8a 02 18 brset (0x008A), 0x02, [0xE613] e5fb 12 3a 80 14 brset (0x003A), 0x80, [0xE613] e5ff 12 11 20 10 brset (0x0011), 0x20, [0xE613] e603 12 12 40 0c brset (0x0012), 0x40, [0xE613] ; Manual Switch e607 12 11 40 08 brset (0x0011), 0x40, [0xE613] ; Economy Switch e60b 96 4d ldaa (0x004D) e60d 84 07 anda 0x07 e60f 81 03 cmpa 0x03 ; Stick in position D,3 or 2 e611 25 03 bcs [0xE616] e613 5f clrb Branch Target from e5f7, e5fb, e5ff, e603, e607 e614 20 47 bra [0xE65D] e616 5f clrb Branch Target from e611 e617 ce c8 fe ldx 0xC8FE e61a 96 18 ldaa (0x0018) e61c 5f clrb e61d a1 00 cmpa (X+0x00) ..... e65d d7 5a stab (0x005A) Branch Target from e614, e656, e65a e65f 39 rts Code:
e76f 12 8a 02 20 brset (0x008A), 0x02, [0xE793] e773 12 3a 80 1c brset (0x003A), 0x80, [0xE793] e777 12 11 20 18 brset (0x0011), 0x20, [0xE793] e77b 12 12 40 14 brset (0x0012), 0x40, [0xE793] ; Manual Switch e77f 13 11 40 04 brclr (0x0011), 0x40, [0xE787] ; Power Switch e783 c6 02 ldab 0x02 e785 20 55 bra [0xE7DC] e787 12 5a 02 08 brset (0x005A), 0x02, [0xE793] e78b 96 4d ldaa (0x004D) e78d 84 07 anda 0x07 e78f 81 03 cmpa 0x03 ; Stick in position D,3 or 2 e791 25 03 bcs [0xE796] e793 5f clrb e794 20 46 bra [0xE7DC] e796 ce c9 04 ldx 0xC904 e799 96 18 ldaa (0x0018) e79b 5f clrb e79c a1 00 cmpa (X+0x00) ..... e7dc d7 5a stab (0x005A) e7de 39 rts As a first attempt, I have modified the UK TCU code as follows: Code:
e5f7 5f clrb e5f8 12 8a 02 61 brset (0x008A), 0x02, [0xE65D] e5fc 12 3a 80 5d brset (0x003A), 0x80, [0xE65D] e600 12 11 20 59 brset (0x0011), 0x20, [0xE65D] e604 12 12 40 55 brset (0x0012), 0x20, [0xE65D] ; Manual Switch e608 12 11 40 04 brset (0x0011), 0x40, [0xE610] ; Economy Switch e60c c6 02 ldab 0x02 e60e 20 4d bra [0xE65D] e610 96 4d lda (0x004D) e612 84 07 anda 0x07 e614 81 03 cmpa 0x03 ; Stick in position D,3 or 2 e616 24 45 bcc [0xE65D] e618 ce c8 fe ldx 0xC8FE e61b 96 18 ldaa (0x0018) e61d a1 00 cmpa (X+0x00) ..... e65d d7 5a stab (0x005A) Branch Target from e5f8, e5fc, e600, e604, e60e, e616, e656, e65a e65f 39 rts In summary, the modified program enables "power mode on demand" when the economy switch is on and "permanent power mode" when the economy switch is off. I think this is potentially a cool mod for the UK and Euro SVXes. However, one problem remains: How do we get the modified program into the TCU. If anybody has any bright ideas about that then I would like to hear them. There is a space laid out on the circuit board to add an EPROM socket. But what type of EPROM? Maybe the same 27C1028 type used by the ECU? And how do you tell the TCU to use the new one rather than the original one? There doesn't seem to be any obvious resistor to cut like on the ECU. Anybody know the answer to this? Or how to go about figuring it out? I really want to test this out.
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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 Last edited by b3lha; 01-24-2008 at 04:59 AM. |
#572
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No, he didn't even ship the adapters to a number of people that paid for them
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Dave - 03 Baja - 92 SVX - 86 Brat - 08 OB 3.0 |
#573
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Quote:
For basic tuning, all that's needed to get started is access to the AFR and timing maps. Subaru's are a bit difficult to tune timing because the ECU activily searches for the optimum timing. The best way to tune the timing is to zero out the correction table before tuning the timing, and then adding the correction values back after the tuning is complete.
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Mychailo :: 2006 Silver Mitsubishi Evolution 9, E85, 34 psi peak, 425wtq/505whp DJ :: 1995 Laguna Blue SVX L AWD 5MT (sold) Visit my locker SVX Mods: ND iridium spark plugs, Impreza RS fpr, afr tuned to 13.2:1 using a custom MAF bypass, custom exhaust, WRX 5MT w/ STi RA 1st-4th gear & stock WRX 5th gear, Exedy 13 lb flywheel & Sport Clutch, STi Group N tranny & engine mounts, urethane spacers in rear subframe, rear diff mounts, and pitch stopper, SVX Sport Strut Springs (185f/150r), custom 19 mm rear swaybar, urethane swaybar mounts, Rota Torque 17x8", 225/45-17 Proxes 4 tires, Axxis Deluxe Plus organic brake pads. |
#574
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I have failed to get onto UpNorth either. As regards the adapter he sent me I have not been able to get it to work so far. I have been busy with the 6 speed install so its delayed any progress so far. I hope to get back to it in a couple of days.
Not sure exactly how the ECU operates with the Air/Fuel, is it that the ECU reads the ratio then looks up a table and adjusts fuel based on that number?
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1995 - SVX 700,000 K Mine, DMS Struts to lift car 2in. Tyres Wrangler Silent Armor 235/70R16, PBR Radiator. 6 speed with DCCD and R180 rer diff, Heavy duty top strut mounts front and rear. Speedo correction box fitted. New stero (gave up on the old one). Back seat removed and 2 spare tyres fitted for desert driving. ECUTune SC sitting in the box for the next SVX. 1992 - SVX 255 K Wife (Want to stay Married so not allowed to fit SC) 1992 - SVX Pearl with black roof race car roll cauge etc ready to race. Ex Tasman Targa car. 1995 - SVX Green low k mint condiation. 1995 - SVX Rally car, ex Matts car. Now to be used on track. 1992 - SVX red & Black being converted to Mid Engine. 1995 - SVX Red 143,000 bit rough. Owned 5 others Subaru back to a 1974 1400 GSR. |
#575
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Tony,
During low power cruise, the ECU operates in closed loop. It checks the afr using the O2 sensors, and adjust the fuel trims to keep the afr at 14.7:1. During "aggresive" driving, (anything more than 20 or 25% throttle on an SVX), the ECU flips into open loop mode. In open loop, it no longer tries to monitor the afr. It just adds fuel according to the fuel map. Fuel maps are typically presented as a table of afr values. These values really just represent injector pulse lengths.
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Mychailo :: 2006 Silver Mitsubishi Evolution 9, E85, 34 psi peak, 425wtq/505whp DJ :: 1995 Laguna Blue SVX L AWD 5MT (sold) Visit my locker SVX Mods: ND iridium spark plugs, Impreza RS fpr, afr tuned to 13.2:1 using a custom MAF bypass, custom exhaust, WRX 5MT w/ STi RA 1st-4th gear & stock WRX 5th gear, Exedy 13 lb flywheel & Sport Clutch, STi Group N tranny & engine mounts, urethane spacers in rear subframe, rear diff mounts, and pitch stopper, SVX Sport Strut Springs (185f/150r), custom 19 mm rear swaybar, urethane swaybar mounts, Rota Torque 17x8", 225/45-17 Proxes 4 tires, Axxis Deluxe Plus organic brake pads. |
#576
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Okay that all make sense, but when I have had a bad O2 sensor I have noted that the car doesn't accelerate smoothly. There for the ECU must be checking the sensor for some reason or have I total got it wrong.
Tony
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1995 - SVX 700,000 K Mine, DMS Struts to lift car 2in. Tyres Wrangler Silent Armor 235/70R16, PBR Radiator. 6 speed with DCCD and R180 rer diff, Heavy duty top strut mounts front and rear. Speedo correction box fitted. New stero (gave up on the old one). Back seat removed and 2 spare tyres fitted for desert driving. ECUTune SC sitting in the box for the next SVX. 1992 - SVX 255 K Wife (Want to stay Married so not allowed to fit SC) 1992 - SVX Pearl with black roof race car roll cauge etc ready to race. Ex Tasman Targa car. 1995 - SVX Green low k mint condiation. 1995 - SVX Rally car, ex Matts car. Now to be used on track. 1992 - SVX red & Black being converted to Mid Engine. 1995 - SVX Red 143,000 bit rough. Owned 5 others Subaru back to a 1974 1400 GSR. |
#577
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As long the car is less than 20-25% throttle, it will want to run in closed loop. If the car has a bad O2 sensor, then it will likely run in limp mode in that throttle range because it can't get a proper O2 reading. It might also run in limp mode at higher throttle positions. I'd have to look at the ROM code to see what its doing.
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Mychailo :: 2006 Silver Mitsubishi Evolution 9, E85, 34 psi peak, 425wtq/505whp DJ :: 1995 Laguna Blue SVX L AWD 5MT (sold) Visit my locker SVX Mods: ND iridium spark plugs, Impreza RS fpr, afr tuned to 13.2:1 using a custom MAF bypass, custom exhaust, WRX 5MT w/ STi RA 1st-4th gear & stock WRX 5th gear, Exedy 13 lb flywheel & Sport Clutch, STi Group N tranny & engine mounts, urethane spacers in rear subframe, rear diff mounts, and pitch stopper, SVX Sport Strut Springs (185f/150r), custom 19 mm rear swaybar, urethane swaybar mounts, Rota Torque 17x8", 225/45-17 Proxes 4 tires, Axxis Deluxe Plus organic brake pads. |
#578
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Have we made anymore progress or is it that everyone is just going to change the ECS to something like the Hydra that is being worked on.
Tony
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1995 - SVX 700,000 K Mine, DMS Struts to lift car 2in. Tyres Wrangler Silent Armor 235/70R16, PBR Radiator. 6 speed with DCCD and R180 rer diff, Heavy duty top strut mounts front and rear. Speedo correction box fitted. New stero (gave up on the old one). Back seat removed and 2 spare tyres fitted for desert driving. ECUTune SC sitting in the box for the next SVX. 1992 - SVX 255 K Wife (Want to stay Married so not allowed to fit SC) 1992 - SVX Pearl with black roof race car roll cauge etc ready to race. Ex Tasman Targa car. 1995 - SVX Green low k mint condiation. 1995 - SVX Rally car, ex Matts car. Now to be used on track. 1992 - SVX red & Black being converted to Mid Engine. 1995 - SVX Red 143,000 bit rough. Owned 5 others Subaru back to a 1974 1400 GSR. |
#579
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Not everyone has that sort of cash, or the necessity. I'd say this project is probably still alive.
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#580
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Quote:
The current state of play is that for diagnostics we have the VWRX software working but it is not ideal. The JDash software is not far from working. The JDash guy kindly wrote some code for the SVX but I haven't had a chance to test it yet. From looking at it, I think it needs a few small tweaks. As far as tuning goes, we know where the fuel, base timing, and advance maps are and maf scaling, and rev and speed limiters. So anyone with a suitable eprom programmer could probably start tuning their engine. However once the ECU has taken the base values from it's maps, it tweaks them based on sensor inputs and learned values. I am currently trying to figure out this process so that we know what exactly what the ECU is doing and why. Otherwise there is no easy way to diagnose the problem if a modified map isn't working as expected.
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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 |
#581
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Quote:
Are those SVX changes to JDash on the trunk? Cheers, -Jeff |
#582
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If there was interest I could roll a version of my 'Realtime' board for the early Subbie ecus, but I don't think there is really a market. The Nissan and Subaru ECUs are so similar it really wouldn't require too many changes. It would let you do SSM and realtime memory changes all over the same USB connection, implemented with an FTDI chipset, so existing SSM programs (not that there are that many, lol) should work just fine. On the editing side it supports TunerProRT (and the emulator protocol is open if you want to roll your own software), so all you'd need is to build b3lha's discoveries into an XDF file.
But at $350-400 I just don't see many early 90s Subbie owners that interested. |
#583
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Phil,
I have been flat out changing the gearbox in my car and fixing a head gasket in my wifes so I haven't got back to the reader. I have been thinking may be we need to build a SVX engine simulator. Suggesting we could use a PLC with different cards then drive the outputs and imputs to the ECU. That way we could get a more accurate start on the data. What do you think would it be worth it? With out sounding stupid are we clear on what we don't know? And are we sure the tables are all correct? Having some involvement with putting a different ECU on to a SVX I am inclined to stick to this one. Calum are you saying the hardwere will cost $350-400? Tony
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1995 - SVX 700,000 K Mine, DMS Struts to lift car 2in. Tyres Wrangler Silent Armor 235/70R16, PBR Radiator. 6 speed with DCCD and R180 rer diff, Heavy duty top strut mounts front and rear. Speedo correction box fitted. New stero (gave up on the old one). Back seat removed and 2 spare tyres fitted for desert driving. ECUTune SC sitting in the box for the next SVX. 1992 - SVX 255 K Wife (Want to stay Married so not allowed to fit SC) 1992 - SVX Pearl with black roof race car roll cauge etc ready to race. Ex Tasman Targa car. 1995 - SVX Green low k mint condiation. 1995 - SVX Rally car, ex Matts car. Now to be used on track. 1992 - SVX red & Black being converted to Mid Engine. 1995 - SVX Red 143,000 bit rough. Owned 5 others Subaru back to a 1974 1400 GSR. |
#584
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Quote:
Building an engine simulator from scratch is beyond 99% of the people out there because you need the pulse patterns. Once you've got that worked out putting together a kit that most people can assemble is easy. If there happens to be an SVX near Lubbock TX (aka the middle of nowhere) I'd be happy to document the pulse patterns and post them up here. Anywho, here's mine for doing Nissan B13/S13/RNN14/HP10s- The little chip with the silver marking is what I actually program to set the correct pulse train. Its just a pic12F629 banging out the correct pattern in a constant loop, then I vary its clock to change the pattern speed (and so adjust the RPM of the 'engine'). The cheesy little multimeter on the side measures the current draw of the ecu. Thats a handy quick and dirty diagnostic for seeing if an ecu has problems. I know from memory what roughly all of the ECUs I work on should draw, so when I bench test a customers ecu I can tell withing a couple of seconds if the core is good or it has problems. The early 90s Nissan ecus in FWD vehicles were located right under the floor heater vent (what a great design, lol), so they tend to suffer water damage from condensation, especially from northern cars. Yea, Realtimes run between $350-400. Exact pricing depends board size, etc. I install for free (and return shipping is free), and encourage people to let me do that. I would need to sell 5 to break even. I suspect that would be tough. Here's what a Realtime board looks like. Lots of itty bitty surface mount stuff. I hand assemble each one. The cable you see at the top is a 6ft USB cable. fun stuff. Last edited by Calum; 02-27-2008 at 09:00 AM. |
#585
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Quote:
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Joe
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Black Betty [Bam a Lam!] '93 UK spec, still languishing Betty Jersey Girl Silver '92 UK [Channel Isles] 40K Jersey Girl @ Mersea Candy Purple Honda Blackbird Plum Dangerous White X2 RVR Mitsubishi 1800GDI. Vantastic 40,000 miles Jersey Girl |
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