Answering questions. Again, this applies to my 95, I can't speak for other years. I would think that everything is the same for at least 95 and under SC400's. 96 and up obdII cars are likely a different ball game altogether.
Originally Posted by RedPhoenix
Where on the tranny is the sensor located. Im thinking about trying it.
Driver's side, on the side of the trans case directly after the bellhousing.
Originally Posted by IS_250
Now, i've got a question? Is it possible to wire a switch to the solenoid so you can swith between a smooth shift and a harder shift?
Maybe even wire into the ECT/PWR switch?
I don't see any reason why you couldn't put a switch on it, I've even thought about doing it myself.
No, I don't think you could wire it to the ECT/PWR switch. There is 12volts going to the switch anytime the ignition is on. Turning the switch to PWR mode sends the 12 volts to the ECU pin 18 and to the indicator light in the cluster. Wiring the solenoid to the switch would allow 12volts to go to the cluster light, the ECU pin 18, the ECU pin 13 (for solenoid 4) and to the solenoid itself which is normally controlled with pulse width modulation. Good chance of frying something.
Originally Posted by 93MSB
I did a bit of skimming through the 95 supra manual. I found that the a340e (2jzge version) only has 3 solenoids solenoid1, solenoid2, and a lock up solenoid. It also does not have the overdrive clutch speed sensor. So the particular method you described will not work for the sc300.
I also took a look at the 2jzgte version of the a340e found in the supra turbos. It has 5 solenoids, 1-4 have the same operations as the 1uzfe and the 5th one is to control line pressure
im going to read more in depth about the 2jzge version of the a340e to see what i can find.
ill be happy to email you the .pdf's for the a340e if you want to have a look at it
I do remember reading somewhere that the SC300 stayed with a mostly manually controlled trans until 97 or 98.
I find it interesting that the 2jzgte trans has 5 solenoids. Seems redundent to have the accumulator bleed off solenoid when the ECU has full contorl over line pressure anyway.
I have access to TIS but definately feel free to post stuff here for the benefit of others.
Originally Posted by andrewwake
so will overdrive/od button still work?
Same goes for tq clutch lock up, trac control, abs ect. I don't have the cruise hooked up on my car but I'd bet it would be fine as well.
Originally Posted by 5sp_jzz30
my buddy did a similar thing on his altima. the transmission didnt like it and started to shift like crap. we had to do a full fluid flush about 3 times to bring it back to stock. maybe our trans is different but the saying is "you cant have the cake and eat it too" there are always downfalls with all positives.
i dont have to worry about this problem though
I do understand the concern...but I think the a340x is a different animal. The only purpose of the no 4 solenoid is to bleed off line pressure during a shift for a smooth shift and to prevent squat. Think about this for a second, what happens when any transmission shifts smoothly......it's slipping. The smoother any given trans shifts, the more it's slipping. As far as preventing vehicle squat, the solenoid is causing enough slip to reduce power to the wheels to keep the car level on take off for a luxury, not sporty feel.
Now on my car I have been running quite a while, including 70+ track runs, with about twice the stock power on the trans and haven't had any problems other than bouncing off the rev limiter during the 1-2 shift at WOT. Also keep in mind that I have .525 inch of shim in both the 1-2 and 2-3 accumulators. AND...I have adjusted the main pressure regulator to up line pressure. I'm still considering adding MORE shims. It definately shifts firmer but could be better.
So, someone with a stock car would probably not see as much of a difference as I have by disabling the solenoid. But, it has made quite a difference. Even with twice stock power and a 2800rpm dragon, I still felt like the car was a bit weak on take off and when downshifting. Now, the car squats like freakin crazy, it actually feels like a high powered sports car.
To go over a few things again. Unplugging the od speed sensor will not hurt anything but it WILL make the overdrive light on the dash blink and there will be a trans code, 67. Cutting the solenoid wire WILL NOT make the overdrive light flash but there will be a trans code in memory, 46. Benefits. You will have more power off the line and when downshifting due to the fact that the ECU is not making the trans slip to REDUCE power. All shifts will be firmer during all driving conditions.