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#31
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Steve - I am now about 90% confident that I'm performing the TCU self-test correctly.
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I was reading the End-Wrench article "4EAT Phase 1 Transmission Diagnosis & Service" looking for a reason that my tranny is not working as advertised: http://endwrench.com/images/pdfs/4EATPh1Win04.pdf On Page 2 & 3 it discusses the sensor inputs for the TCU. For the Temperature sensor it says: "When the ATF is hot (AWD only), the TCU shifts the transmission as if in the POWER mode. This pushes the shift points higher which allows the engine to run faster. The oil pump then circulates ATF through the oil cooler more quickly so as not to overheat the engine coolant." After reading this I wonder, what if my temperature sensor is defective and it provides the TCU with an incorrect/hot temperature input. If this is happening, is the TCU also keeping the TC from locking up, in order to keep the ATF flowing? Would this also inhibit the Power Mode switching when I try to kick it in with the throttle, since the TCU had already set up the tranny in Power mode? If this is the case, would the TCU self-test ignore this as a problem since it would see a temperature sensor that was working, regardless that it was getting a hot reading from the sensor? Also, what would happen to the Power Light when running the self-test with a hot temperature sensor reading? Would the Power Light stay on all the time (like mine does) and not blink like it should during a normal self-test? What do you think? How can I test the temperature sensor? Looking at the wiring diagram it looks like I can make a resistance measurement at the TCU connector to determine this. The only problems are knowing what the correct reading is suppose to be at ambient temperature, and getting to the TCU connector up under the dash to make the measurement. A little background on this car, a new TCU was installed in '01 at 86,000 miles and the tranny was rebuilt 18 months later at 103,000 miles by Camino Transmissions in San Diego. The clock is now at 125,000 miles. The previous owner said that he has never seen the TC lock-up. Camino told me to stop by and they would look at it (unfortunately they are located 2,000 miles away from here)! - Jim |
#32
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Jim I too have read that from endwrench. It is a great article for in site to the 4EAT transmission.
If the light does not come on at all I would replace the light bulb first. Pull the gagues out. I have not done that yet. To the lock up I would do a test on the Throttle Positioning Sensor. It is the black thing with the brown plug. There are three wires. Tap off the middle wire, I used a custom bend paper clip, and a Volt Ohms Meter. You should read .5 with the ignition turned on and car NOT running. It is not the adjust by loosening the two screws and rotating, little bit at a time. When you reach .5V tighten down the screws and go for a drive. I have a good temp sensor if you want it. Let me know. Steve Picture stolen from SVXFiles
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92 SVX AWD 130,000 w/ rebuilt SVX 4.11 97 Audi A4 1.8T (Daily Driver) 03 Ford Expedition(hers) SVXepidia SVX information warehouse Are you in? My Old Locker A 4.11 Founding Father "Tranny #6" I really need a manual Reading IX [SIGPIC][/SIGPIC] Ya I was there
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#33
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I guess I didn't explain too well. The Power Light does come on, the bulb is OK. That's the problem, it never goes off or blinks.
I can do the TPS check. I've thought about it before, but I wonder if it is really the problem. Wouldn't there be other problems with the tranny, or other systems if the TPS is mis-adjusted? The reason I say this is bacause the whole car is fantastic otherwise. I have never had a tranny that had such great shifting properties, both up shifting and down. Likewise the engine is an outstanding performer. Because of this I really don't want to screw anything up by making any adjustments until I am really sure it's the problem (I guess I'm just a very conservative engineer - if it ain't broke, don't break it)! Do you think my AT temperature sensor theory has any merit? Do you know where I could find out the resistance of a healthy sensor? - Jim |
#34
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No, I just can not read.
I have am not sure but there is a sure fire way to know what is wrong. Let the subie dealer hook there computer up to it. They can run all the selenoids ans sensor test to see what is wrong. It wil also check the computer. Cost is about $100.00 up here in MN. I had a problem with over heating, the dealer mech thought it was a temp sensor but when he ran the computer is was an inline fuse for the A/C fan. Go figure. Steve
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92 SVX AWD 130,000 w/ rebuilt SVX 4.11 97 Audi A4 1.8T (Daily Driver) 03 Ford Expedition(hers) SVXepidia SVX information warehouse Are you in? My Old Locker A 4.11 Founding Father "Tranny #6" I really need a manual Reading IX [SIGPIC][/SIGPIC] Ya I was there
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#35
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OK, I guess you are right. A good friend of mine is the Service Manager for our closest dealer. He also drives an SVX. I'll try to get over there in the next couple of days and see what they can find.
Thanks for your help. - Jim |
#36
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I've finally gotten back to this problem. I'm in the middle of pulling off the intake manifold to replace all the vacuum lines that after 13 years have the physical properties of "glass". Since I had the throttle body on the work bench I decided to pull the TPS off and make some measurements.
I measured the resistance between pins 2 and 3 as shown in the How-To section and here . My Chilton manual says that the throttle closed resistance should be 10K - 12K and wide-open it should be 3K -5K. These values seem to conflict the values in the How-To which seem to be about 5K with the throttle closed and 1.5K at wide-open throttle. Can someone with a FSM verify what the factory says the pin 2-3 measurements should be? The measurements on my TPS are way off from both of the above sources. I measure 870 ohms at closed throttle and 4.75K at wide-open throttle. I also can see an obvious problem when I move the throttle. A little above idle as the resistance is increasing it suddenly decreases for a couple of degrees of movement and then continues to increase toward wide-open throttle - Yikes! So I assume (er..... that is, hope) that this is the source of my transmission problems. If it is, it will also be the source of a $150 hole in my wallet. - Jim
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- Jim '02 Outback - Wife's car '96 Legacy Wagon - Son's car '95 Legacy Sedan - #5 Daughter's car '93 Impreza Sedan - #4 Daughter's car '92 Claret LS-L - My car ____________ TOTAL = 595,000 Subi miles |
#37
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Tps.
Jim the book doesn't say what the resistance is, just the voltage output when connected. I wouldn't worry about the exact resistance, but I reckon the sudden change in resistance as it sweeps across, is a real problem. This can make the trans think you are going for Power mode, every time it hits this spot.
Think you have found it. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#38
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Thanks for verifying my assumption Harvey. I would probably be better off getting a new one. Since it is a wear item, With a used TPS I would most likely end up with the same problem in the near future.
At least it won't keep my car off the road until I scare-up enough funds to replace it. - Jim
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- Jim '02 Outback - Wife's car '96 Legacy Wagon - Son's car '95 Legacy Sedan - #5 Daughter's car '93 Impreza Sedan - #4 Daughter's car '92 Claret LS-L - My car ____________ TOTAL = 595,000 Subi miles |
#39
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Is there a common thread?
My original post on this thread concerned 2 "features" that are missing with my transmission. Now I have discovered that I also have third feature that is missing -- AWD. Seldom do I take my Claret out in the rain. However last week I did, and I discovered that my AWD is missing in action. All I have is full-time FWD. The front wheels spin and the rear end just sits there, going along for the ride.
So to recap, my transmission is missing these features: - No Power Mode changes with accelerator punch - No Torque Converter lock-up - No AWD At the same time this is happening the transmission still shifts great, With normal driving you would never know there was anything wrong. However the transmission doesn't seem to know that it has a problem. It never gives me the dreaded 16 blinks. In fact when I run the diagnostic test I don't get any blinks. The test instructions say that with no problems you should get a blink every 1/4 second. My Power Light just sits there and stares at me the whole time I run the diagnostic test. I disconnected the resistor and started the car to see if my transmission can detect any problems. I immediately got the 16 blinks on the Power Light. However when I ran the diagnostics there was no change. It detected no failures, and the test for previous problems showed nothing. I also drove it without the resistor and there was no difference in the transmission operation. Shifting seemed to be normal, no difference with the resistor plugged in, or not. I reconnected the resistor and now the 16 blinks are gone. So........ I have no Power Mode, no TC lock-up, no AWD, and no TCU problem detection capability. It makes me wonder if I have a Subaru transmission. Or do I have a bad TCU. How do I determine if it is bad without buying a $500 computer? I can't believe that a bad TPS could be the root of all these issues. Does anyone have any other ideas? Thanks - Jim
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- Jim '02 Outback - Wife's car '96 Legacy Wagon - Son's car '95 Legacy Sedan - #5 Daughter's car '93 Impreza Sedan - #4 Daughter's car '92 Claret LS-L - My car ____________ TOTAL = 595,000 Subi miles Last edited by JIMSVX; 11-06-2005 at 09:26 PM. |
#40
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Hi Jim
Sorry to hear the problems you are having. I am also located in St Louis. If you want to comeby and swap parts to troubleshoot the problem, no need to spend all that $$$ just to see if it will work. I have 2 SVX( just got one last week). PM me. Denny |
#41
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This might be a really dumb question..but have you checked the FWD fuse slot to make sure that the fuse isn't in there?
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-Jason (8/23/07-Present) 1995 Subaru SVX LSi (197k) Polo Green (#1102) 03/95 Mods: DDM Tuning 4500k 35w Low Beam HID, 100w H3 Bulbs, Extra Ground Cables, 15 minute $12.96 mod, svxfiles designed transmission mount (), sporting a "new" tail light bar, silver BBS rims, custom power steering cooler (one that doesn't dump ATF constantly), new negative lead cable, no more third or fourth gear (1977-Present) 1977 Chevrolet Corvette (81k) Silver (12/01/2011-Present) 2005 Subaru Outback 2.5i Limited 5MT (97k) I have a bad feeling about this. -Obi Wan Kenobi |
#42
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Quote:
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- Jim
__________________
- Jim '02 Outback - Wife's car '96 Legacy Wagon - Son's car '95 Legacy Sedan - #5 Daughter's car '93 Impreza Sedan - #4 Daughter's car '92 Claret LS-L - My car ____________ TOTAL = 595,000 Subi miles |
#43
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My power light does the same thing...is on when i turn the key, but turns off and never comes back on while i am driving. Does the power mode even make a big difference in accelerating? Is it worth trying to fix?
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#44
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When my '93 Impreza (110 HP) was my everyday driver I used the Power Mode at least once everytime I drove it. However, with the SVX I wonder if I'm really missing anything. With the standard shift points it's about as agressive as I need.
But, I would like to have the car setup like it came out of the factory. - Jim
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- Jim '02 Outback - Wife's car '96 Legacy Wagon - Son's car '95 Legacy Sedan - #5 Daughter's car '93 Impreza Sedan - #4 Daughter's car '92 Claret LS-L - My car ____________ TOTAL = 595,000 Subi miles |
#45
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So the Power Mode adjusts how the transmission shifts when you step on the gas? My 1994 SVX LSi already seems to shift right for quick acceleration, but the light does not turn on.
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