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VVTI Tiptronic Gearbox Info


MattP

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I'm currently routing around these dash innards for a solution if all fails Il Torch the devil spawn thing...

 

Sometimes I wish I bought a manual :(

 

Should've just bought a normal auto, those tiptronic buttons are cack, your having some hassle with this thing no wonder Andrews thinking of dumping it for a nissan

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Since bloody day one this box has been no less than a B###### but when it works it works better than a lethargic clunky manual...

 

 

As always I shall have my victory this box will do as it is told..

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Since bloody day one this box has been no less than a B######

 

You said it right there. ;)

 

Someone probably abused the downshift in manual mode from third to second on the stick and overheated the box, causing whatever it is that happens when you overheat an auto gearbox :think: - 'component failure', that's it! :sly:

 

The electronics won't allow high revving downshifts to protect the internals so it could be overheating damage from thrashing about in second for too long. It is very addictive afterall!

 

I'd fit a decent transmission oil cooler whilst you're under there if you have time. Good insurance.

 

Heat is the number one enemy of mechanical systems, particularly in the case of auto gearboxes apparently.

 

Look for any signs of cracked 'o' ring seals and such that may be causing a leak or loss of fluid pressure and subsequent failure to engage manual control because the ECU's are sensing a fault. These things are highly self-protective but in manual mode you can't stop people from over-revving for long periods and burning stuff up.

 

An OBDII reader or proper diagnostics should surely help?

 

Ditto the 'check the wiring' comments but I blame overheating abuse, which of course could cause bad connectors in the box perhaps. The display should still show manual gear number selection when the stick is shifted to the right out of D into M, as Chris said so I would suspect the shift sensor on the stick unit itself, since it's microswitched and not mechanical from the feel of it.

 

I've never had any issues with my Tiptronic in 4 years but I only use manual mode for engine braking in slow traffic to hold it in low gears and avoid constant braking/accelerating cycles. 94k miles and still drives like new, not that I ever drove a new one. Still speed limited which also keeps the engine and gearbox in good condition, since high rev's = overheating.

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You said it right there. ;)

 

Someone probably abused the downshift in manual mode from third to second on the stick and overheated the box, causing whatever it is that happens when you overheat an auto gearbox :think: - 'component failure', that's it! :sly:

 

The electronics won't allow high revving downshifts to protect the internals so it could be overheating damage from thrashing about in second for too long. It is very addictive afterall!

 

I'd fit a decent transmission oil cooler whilst you're under there if you have time. Good insurance.

 

Heat is the number one enemy of mechanical systems, particularly in the case of auto gearboxes apparently.

 

Look for any signs of cracked 'o' ring seals and such that may be causing a leak or loss of fluid pressure and subsequent failure to engage manual control because the ECU's are sensing a fault. These things are highly self-protective but in manual mode you can't stop people from over-revving for long periods and burning stuff up.

 

An OBDII reader or proper diagnostics should surely help?

 

Ditto the 'check the wiring' comments but I blame overheating abuse, which of course could cause bad connectors in the box perhaps. The display should still show manual gear number selection when the stick is shifted to the right out of D into M, as Chris said so I would suspect the shift sensor on the stick unit itself, since it's microswitched and not mechanical from the feel of it.

 

I've never had any issues with my Tiptronic in 4 years but I only use manual mode for engine braking in slow traffic to hold it in low gears and avoid constant braking/accelerating cycles. 94k miles and still drives like new, not that I ever drove a new one. Still speed limited which also keeps the engine and gearbox in good condition, since high rev's = overheating.

 

 

I dont think Overheating is the issue hear at all I have had the car 3 years and have not observed any symptyms relating to Overheating the car spends most of its time at 30mph in fully auto mode, and as most of the northern members know it gets an easy life by no means a high revving street racer haha.

 

As mentioned the car worked fine and still does drive flawlessly in full auto mode its silky smooth it just wont allow tiptronic control...

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Anyway its been a long day I have pulled the dash out and checked the wiring to the ECU and the Auto Lever microswitch as shown below...

 

image

 

 

 

In conclusion I believe the lever and wiring of buttons etc are fine.

 

 

Moving on I checked the outside of the box for any evidence of damage or dodgy connections again it looked fine and I removed the sump cover to show the following..

 

 

All 3 Photos show the internals of the box with the Filter/Strainer removed I found no metal attached to the magnets in the sump nor did I find any non magnetic particles in the sump on removal, I did find the internals had a thin layer of grey dirt that simply wipes off but nothing major...

 

 

As can be seen I believe there are 7 solenoids and what appears to be some kind of sensor. Not the usual 5 solenoids found in the TT autobox

 

Suspected Solenoids I have placed RED Crosses on.

 

Suspected Sensor I have Ringed in Yellow.

 

 

I have left the car as is for the moment pending you lot taking a gander im in unknown territory here.

 

 

image

 

image

 

image

Edited by MattP (see edit history)
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Excuse a slow response, I've been out all day.

 

 

Did you confirm a signal from the buttons to the ECU?

 

 

That's the cleanest transmission I've seen, there's not much wrong with that.

 

Whilst your in there you might as well remove the solenoids and give them a blast through with carburetor cleaner, do them one at a time and refit to ensure that you don't get them muddled up. Some are normally open valves and others are normally closed, if there was a problem with a solenoid there should be a fault code flashing.

 

Go over the valve-body and torque up all the bolts to 7ftlb, they grow slack with time, sump bolts are 6.5ftlb and don't exceed it.

 

You could check continuity of wires back to ECU. and check that the solenoids are functioning and then you'll have run out of things you can check.

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The only thing I get when I do the diagnostic is a fault code 76 which according to our fault code list does not exist?

 

Is it possible to clean all this gear up and connect the battery...

 

Bear with me hear..

 

1.And turn the ignition to the on position but not start

 

2.drop the gear selector into D and across to M and see if that gives me a gear read out.

 

Or would it not work without the dump pan and fluid in?

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If it were my car I would be looking to the electrics rather then the hyydro-mechanics, but that's just how I would slant the diagnostics.

 

Cavet: It's 1.31 AM and I am just back from a boozy party ;)

 

 

That's where I started Chris I have the car in bits again seats,dash,carpet etc is all out.

 

This new wiring diagram I have shows the pinouts and even has a brief explanation of what they should be doing which is nice...

 

 

I needed to get into the auto sump regardless to swap the filter/strainer as sad as it sounds I do rather enjoy learning about the innards of the Autobox.

 

Il report back later today with my progress.

Edited by MattP (see edit history)
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What do you make of the extra 2 solenoids Dave are they what you expected?

 

I suspected differences in valve-body, but the transmission is same, good to see a pic of one at last.

 

The later the model of transmission, the more solenoids appear in the valve body, the 5-speed Lexus boxes have 7 too, I'll take a pic of one of those next weekend.

 

Whilst the solenoids are out for a clean, run 5 volts through each one and confirm that they all open or close.

 

The fault code 76 could be a dicky 6th or 7th solenoid, the checks above will decide.

Edited by David P (see edit history)
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This thread is rapidly putting me off the get a vvti idea:blink:

 

Don't worry, if you find a decent one that works when you buy it, the chances are it will continue to do so if maintained properly, like anything else.

 

I've never driven a normal TT Supra so can't compare the acceleration but the low end torque is monstrous. I can (all too) easily smoke both rear tyres from a standstill on dry tarmac by nearly flooring it.

 

Also the blue top cover looks really cool! :D

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This thread is rapidly putting me off the get a vvti idea:blink:

 

I dare say this is one of the best kept VVTI Tips on here it's owner throws money at it for general maintenance like you wouldn't believe.

 

But the car sits for 6 months at a time during winter and it can let dirt in the oil settle etc cars do strange things when sat. This car is by far better than the two Supras I used to own but they never kicked like this one ;)

 

 

I suppose most people from what I have seen on here would just leave this issue and not rectify it but the owner has told me to sort it so sort it I shall one way or another.

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Being VVTi isn't the issue, it's the fact that these Tiptronics were never sold in English markets and so they aren't well understood. But having owned a UK TT auto, I can tell you that the Tiptronic VVTi cars really moved the game on.

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Being VVTi isn't the issue, it's the fact that these Tiptronics were never sold in English markets and so they aren't well understood. But having owned a UK TT auto, I can tell you that the Tiptronic VVTi cars really moved the game on.

 

And that..

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