Hi all.

I have been reading this thread with interest. It seems there are a few people in here who know the A340E transmission.

I have a few questions with regards to the function of the solenoids in the later version of this transmission, such as the version fitted to the 1998 onwards Supra that was labelled 'tiptronic'.

According to the information I can find, this trans has solenoids as follows:
S1 - Shift Solenoid 1
S2 - Shift Solenoid 2
S3 - Shift Solenoid 3 (sometimes shown as SD)
S4 - Shift Solenoid 4
SLT - Line Pressure
SLU - Lockup
SLN - Accumulator Back Pressure


Can anyone shed some light on what S3 & S4 do?

Thanks

 

^^ I'd like to help you but I don't know the later model A340 that well.

I wrote this in my build thread. Thought I'd share it here in regards to the 4th solenoid and Transgo shift kit:

I have the 4th solenoid mod wired on a switch. When the solenoid is off, you can really tell the increased line pressure through the transmission. By moving the shift lever from park to drive it really jerks hard into drive. With the solenoid on, it doesn't have this huge jerk. Since I have the Transgo Shift Kit I already have boosted line pressure so the effects of the 4th solenoid mod are more pronounced. Although I do notice the increased line pressure when switching from park to drive, the increased line pressure is not noticed when going WOT or changing gears. This is probably because the 4th solenoid is there to gradually increase the line pressure. So with the 4th solenoid set to on, my line pressure at a stop is normal and then increased to full line pressure when shifting at WOT. With the 4th solenoid mod off, my line pressure is at max all the time.

For these reasons, I actually just drive around with the 4th solenoid mod ON like stock. I have comfortable lexus like shifting at low speed and great crisp shifting with the Transgo at WOT. I have to do further testing if the increased pressure of the 4th solenoid mod gives me better times, but to be honest from a seat of the pants feeling it does not. I could see if someone did not have the Transgo kit, that the 4th solenoid mod would be a very small upgrade. The 4th solenoid mod however does not compare to the effect of the Transgo shift kit at all.

I have the Hot Rod setting on my Transgo kit. The hot rod setting is simply the size you drill the holes in your valve body. The kit comes with two drill bits; Truck sized and Hot Rod sized. The hot sized are larger and will make your auto chirp your tires during WOT shifts. It is a great setting for fun but for all out 1/4 mile time performance it is probably not. I think a drill size between truck and hot rod would be ideal. I've never tried truck setting, but if you were you could start with it and then go up from there. I'd imagine a drill bit size right under Hot Rod would be just perfect. I'm just worried when I slap on my supercharger that my rear is going to get squirly on shfits with Hot Rod settings. Transgo shift kit a huge thumbs up.

 

I realize I've only been on CL for three months, but how the **** did I miss this mod until now?! My major wish list items have been a torque converter or manual transmission swap, so as to unleash the torque potential of this wonderful V8. Let's see, $1,000-3,000 or free... Easy choice. I went ahead and clipped wire #13 and am definitely liking it so far. I've never been able to squeal the back tires in a straight line acceleration on dry pavement before, and it pushes me back in my seat nicely now, like a V8 should.

I'm trying to decide between: a) leaving the wire cut, b) splicing in a spare rocker switch I've got lying around, or c) tying it into the PWR/NORM switch. I read through the whole thread and didn't see anyone answer the handful of questions how to do the latter. That switch has four pins. Which ones would you tap? Of course, going that route means you'd have to be in PWR mode to get the full benefit of the solenoid bypass for beating minivans off the line, and redlining the shifts isn't always desirable (nor is potentially lowered mpg across the board), so maybe it's best to keep them separate.

Anyone try wiring it to the stock stereo's Power button? Only problem there is it would be next to impossible to tell when it's on or off, other than by hitting the gas and seeing what happens.

 

can someone please post a picture of where this wire is and where to cut it? i'm definitely gonna rocker switch it cz my 0-60 right now is 8.2 seconds, should be 7 according to lexus. so hopefully that will help a little. an oil change, spark plugs, and TB cleaning are on the way as well.

 

Somehow I knew you would be the first person to post to this thread following me.

Here's where I first learned of the mod today; complete with pictures:

https://www.clublexus.com/forums/per...lator-vsv.html

Also, in this thread, posts #53 and #112 have info on the #13 wire to cut.

 

post #3 has a picture. i'll be cutting that then, routing a wire to a switch to the glove box and i'll have different tranny modes! WOO!!!

 

if i have a switch, im wondering if it will harm the car at all? like should i turn the car off before switching it or would it be fine while driving? don't wanna harm the tranny since it has 220k miles on it lol

 

That's a good question. I would think you'd want to be stationary when switching it to avoid sending abrupt on/off signals to the solenoid that is designed to gradually bleed pressure. As long as the car isn't moving, I can't think of any good reason you would need to shut off power.

I'm thinking of putting my spare shift bezel in and using the TRAC button (I don't have seat heaters or traction control) as a solenoid toggle. But, I'll need to see if I have the necessary wiring in place to get power to it -- might be as simple as adding that fuse -- to light up the bulb for a normal/override indicator. While I'm searching for it, does anyone know what the four wires represent on the TRAC button? Red, white/black, green, and green/white.

I could call it the anti-traction button.

 

Can someone please post a pinout for obd2? Trying to do this to my sc, but cant figure out which wire it is.

 

Read through the thread. It's been mentioned a few times that OBDII is a whole different beast. I don't remember seeing that anyone ever solved it.

 

A few people stated that cutting the wire at the ecu resulted in a cel, but otherwise worked fine. I just would like to know how they figured out the correct wire.

 

Green with a red stripe on the big 80 pin plug. #13 when you're looking at the the front that goes into the ecu. Did it on my 97 and take off is much better but CEL is on all the time for the solenoid. Other than that it's perfect.

 

I'm going to wire a switch but I assume I'll have to clear the code EVERY time I use it.. Hmm, I hate dash lights...

 

Maybe you can wire your solenoid switch to also be a CEL switch. Out of sight, out of mind.

 

I did it 2 days ago and I like it. The hard downshift is just mildly annoying but I will easily get used to it. I'm no mechanic but it feels like it's my roasted diff bushings allowing my diff to rock causing the knock? I wonder how new diff bushings, motor mounts, tranny mounts would effect this. Would the more solid drivetrain transfer more shock, or would the lack of flex make things smoother because it's tight? I am also considering the switch and would also like to know for sure if I have to stop the car or turn off the car to safely switch it? Whats a super cool switch I could buy?