R34 Tiptronic Transmission Problems

[scotty014]

sorry for all the questions but i cant find that plug. is it connected near the black pan of the gearbox or up closer to the engine?

edit: also what does the speed sensor do? because i cant feel any difference while driving it.

[scotty014]

im back again lol. i forgot i had the service manual on my hard drive so i checked it out but i still cant really find this speed sensor. what it does is i let the car run for a bit then turn it off then when i go to turn it on it flashes, then i turn it off then when i flick it to on again it is all normal. if it is an error wouldnt it stay flashing all the time?

[jayr]

hi guys..i did some self diagnostic today...4-8 flash, shift solenoid A and a/t fluid temp sensor,tcm power supply or throttle position sensor power supply.

then i repeatedly did the selp diagnose came up with 13 A/T flash shift control unit..

can you pls roughly tell me what i need and how much this will cost me...thank you again...

[666DAN]

im back again lol. i forgot i had the service manual on my hard drive so i checked it out but i still cant really find this speed sensor. what it does is i let the car run for a bit then turn it off then when i go to turn it on it flashes, then i turn it off then when i flick it to on again it is all normal. if it is an error wouldnt it stay flashing all the time?

Sorry led you astray, the manual one is a different colour to the auto one :S

You need to look on the drivers side of the car, you'll see a grey right-angled plug going into a black round thing (sensor) attached to the gearbox housing. It's pretty much next to the gearbox support that runs between the transimission oil pan and the CAT (drivers side though!!!) It also has an exhaust mount attached to it on the passenger side.

[666DAN]

hi guys..i did some self diagnostic today...4-8 flash, shift solenoid A and a/t fluid temp sensor,tcm power supply or throttle position sensor power supply.

then i repeatedly did the selp diagnose came up with 13 A/T flash shift control unit..

can you pls roughly tell me what i need and how much this will cost me...thank you again...

Clear the memory, have a drive then read again. I'd say a couple of those errors may be old ones that are stored. But I'd say that the shift solenoids are rooted if it has recorded it at some point.

The other errors can be from previous owners unplugging shit, especially the TPS and TCM power errors. Though they can be caused by a dodgy 5v supply that feeds both of the units.

[scotty014]

Sorry led you astray, the manual one is a different colour to the auto one :S

You need to look on the drivers side of the car, you'll see a grey right-angled plug going into a black round thing (sensor) attached to the gearbox housing. It's pretty much next to the gearbox support that runs between the transimission oil pan and the CAT (drivers side though!!!) It also has an exhaust mount attached to it on the passenger side.

thanks heaps i finally found it i was looking up closer to the front of the car lol. is that speed sensor 1 or speed sensor 2 that ive finally found?

[666DAN]

That's Sensor 1, main output shaft

[jayr]

HELLO AGAIN...how do i reset it?by going for a drive?lol sorry...the car is on limped mode stock in 3rd gear...tnx

[nzboy]

oh no, I got this problem today too. I didnt rape it or anything but drove for a long distance. And on my way back only had 4th gear and it didnt change to any others. Basically at traffic lights i had to pull out from 4th gear. Its a 98 25GT and done about 140xxx. Never had this problem before. But when I got home turned the engine back off and turned it back on again and it worked fine and gears changed normally.

any ideas?

[QLDR31]

I'm experiencing a similar problem with my auto S2 Stagea RS4 (4WD RB25DET NEO).

I have read most of the comments on this thread.

Occationally the A/T light would come on and the fun would end.

This would occationally happen when doing a U turn or other turns or other random events.

I also notice sometimes when turning a corner power isn't 100% (with A/T light off). Not sure if this is normal.

I hooked up a diagnostic tool and it came up with no errors.

I noticed that when you turn the ignition off then on after the A/T light had come on, the A/T light would flash.

After reading the manual my understanding is it flashes 13 times if there was a problem. If the A/T light flashes longer for certain steps, this means that part is faulty.

Flashing Order Malfunctioning unit and circuit

============== ===============================

1..............Vehicle Speed Sensor 1

2..............Vehicle Speed Sensor 2

3..............Throttle position sensor

4..............Shift solenoid A

5..............Shift solenoid B

6..............Overrun clutch solenoid

7..............Lock-up solenoid

8..............A/T fluid temp sensor, TCM power supply, or throttle position sensor power supply

9..............Engine speed signal

10............(RB20E Line pressure solenoid) (Except RB20E Turbine sensor)

11............(Except RB20E Line pressure solenoid)

12............(Except RB20E Total control signal)

13............(Except RB20E Shift control unit)

You have to have the sight of an eagle to actually catch the problem. Maybe record it with a video camera.

The wagons getting worse now so I think I might take it to a specialist to get fixed.

I'm a bit scared to do that after reading Dlyby77's problems. Sounded like the people he took it to didn't really have a clue. I don't understand how someone could blow up an ECU.

Might be better off trying to fix it myself. R34Gtt4dr's comments on this thread seem very helpful.

Though I think it is still under warranty so i'll have a crack at that first.

I will let you know the outcome.

Brendan

Edited August 9, 2010 by QLDR31

[QLDR31]

Not sure about the flashing sequence.

On the stagea the A/T light came on for a short while (probably doing a lamp test), then started flashing 16 times ?

I played the AVI video in slow motion all flashes seem about the same duration. So not sure whats wrong.

Maybe because it's a 4wd it has more flashes?

Got it booked in for an inspection on Friday.

[bubba]

The 16 flashes just mean there is a problem, you have to put it in to diagnostics mode to get the error code flashes.

The sequence is in the R34 service manual, if you can't find it shoot me a PM and I'll dig it out when I get home.

I had an issue where I unplugged the ECU (TCM is in the ECU) without disconnecting the battery (my bad), all of a sudden I was getting A/T errors, first it said Shift Solenoid B and Lockup Solenoid, I was like WTF! Disconnected battery, drained power, unplugged/replugged ECU then it tried to tell me the TCM was fubar'd, reset it again and was all good.

I would suggest making sure the -ve battery clamp is on nice and tight, ages ago I was getting random dropouts as far as power and A/T went, engine would cut out briefly or transmission go in to limp mode, turns out the -ve clamp was a bit loose and was causing things to lose power over some bumps or heavy braking.

[QLDR31]

Thanks

I'll have a crack at doing the diagnostic check, Yeah those errors codes above were taken from the R34 service manual.

Unplugging the battery for a while wouldn't hurt to try.

Took it to a mechanic today, they gave it a service and said shes stuffed. Not sure why they bothered servicing it but anyway.

[QLDR31]

I did the diagnostic check.

Seemed like 4 (Shift solenoid A) and 13 (Shift control unit) have problems.

Does that mean its just a solenoid, Whats the shift control unit ? Is that the ECU ?

The diagnostic led flash could be viewed quite easily, I got the following:

One long flash (think this just means the start of sequence), then got fourteen pulses, with the fourth and thirteenth being longer.

It then kept on repeating this in a loop (with a long pause between loops) until I turned the car off.

[bubba]

Try disconnecting the battery, pump brake pedal a few times, reconnect battery and run diagnostics again, see if you get any errors and if they are the same.

Yes the Shift Control Unit is part of the ECU.

[QLDR31]

Yeah I removed the battery terminal etc.

I went for a drive etc to warm it up.

Now I can't for some reason get the diagnostic to work, must have fluked it the first time.

Tried over 10 times.

One of the issues might be the car alarm interfering with the sequence. Starts flashing alarm when after on off sequence.

By turn ignition on off, that doesn't mean start the engine right? Maybe im doing it too quick?

Another thing it says release the accelerator pedal, it doesn't say anywhere to press the accelerator.

I can't put the gear into D with the ignition off.

Thanks for your help

Brendan

[bubba]

IGN ON means turn the key to the ON position, not start the engine.

Forget about the first "release" of accel. pedal, I assume they just mean make sure it's not pressed at that point.

To get the car out Park with the IGN off, you have to push the red SHIFT LOCK button next to the shifter.

Edited August 19, 2010 by bubba

[InspectorGadget]

Hi All,

You can add my car to the list having these kinds of problems. I imported the car into NZ at 45k and noticed an intermittent issue with the AT shortly after which would occur about every six months or so. It would generally occur when the following sequence of events had happened:

1) The vehicle was brought up to operating temperatures and run for an extended period of time at motorway speeds.

2) The vehicle was then stopped and turned off for at least 20 minutes or longer and allowed to partially cool.

3) It was then taken for another run at a minimum of 100Kp/h. If it was carrying a bit of load, that also exacerbated it.

4) More likely to happen in the summer months.

Currently the car has about 145K on it and I have had one solenoid kit go (definitely a faulty shift solenoid "A"). The symptoms of that were quite different in that every time you got to over 105Kp/h for more than about 5 minutes, you were guaranteed to see the AT light come on. As you guys have worked out, this is a separate issue.

To date the work I have had done is as follows:

1) Take the car into an auto-trans shop with the light on. Using their diagnostic computer, it spits out a fault code for Shift Solenoid "A".

2) The auto-trans shop retested the fresh solenoid pack and confirmed that this was operating normally. They then sent me to an auto-electrician

3) The auto electrician tested the wiring loom inside the auto trans (OK), retested the solenoids (OK).

4) I was able to locate a full workshop manual for the R34 on the internet and supply this to the auto-electrician. This contained a wiring diagram for the tiptronic auto-trans used in the R34. Through this they were able to work out that the only other component in the same circuit 'Shift Solenoid "A"' is a "Shift Solenoid A Pressure Detection Switch" (PN 31041-4AX01 I believe), which they figure must be the cause of the problem. It is interesting to note that there are two pressure switches in the auto-trans, but only one will generate a unique fault code clearly stating that it is a auto trans pressure switch issue. The second one, and the one that I believe we are all having problems with, trips the fault code for the Shift Solenoid A, fires up the AT light on the dash, and puts the car into "Limp Home Mode". This obviously makes diagnosing the issue a bit harder, especially when this type of code is not stored when the vehicle is turned off.

So, right now I have a new pressure switch in my glove box waiting for me to get annoyed enough with the car want to put it in. The switch cost me NZ$150 ex Japan, and the auto-electrician tells me that it is buried inside the trans somewhere, and they will need the help of a transmission specialist to get to it.

I have attached the wiring diagram and circled the component I think is the source of our problems.

Your thoughts?

InspectorGadget

R34_Wiring_Diagram.pdf

[RS4StagMan]

Hi All,

You can add my car to the list having these kinds of problems. I imported the car into NZ at 45k and noticed an intermittent issue with the AT shortly after which would occur about every six months or so. It would generally occur when the following sequence of events had happened:

1) The vehicle was brought up to operating temperatures and run for an extended period of time at motorway speeds.

2) The vehicle was then stopped and turned off for at least 20 minutes or longer and allowed to partially cool.

3) It was then taken for another run at a minimum of 100Kp/h. If it was carrying a bit of load, that also exacerbated it.

4) More likely to happen in the summer months.

Currently the car has about 145K on it and I have had one solenoid kit go (definitely a faulty shift solenoid "A"). The symptoms of that were quite different in that every time you got to over 105Kp/h for more than about 5 minutes, you were guaranteed to see the AT light come on. As you guys have worked out, this is a separate issue.

To date the work I have had done is as follows:

1) Take the car into an auto-trans shop with the light on. Using their diagnostic computer, it spits out a fault code for Shift Solenoid "A".

2) The auto-trans shop retested the fresh solenoid pack and confirmed that this was operating normally. They then sent me to an auto-electrician

3) The auto electrician tested the wiring loom inside the auto trans (OK), retested the solenoids (OK).

4) I was able to locate a full workshop manual for the R34 on the internet and supply this to the auto-electrician. This contained a wiring diagram for the tiptronic auto-trans used in the R34. Through this they were able to work out that the only other component in the same circuit 'Shift Solenoid "A"' is a "Shift Solenoid A Pressure Detection Switch" (PN 31041-4AX01 I believe), which they figure must be the cause of the problem. It is interesting to note that there are two pressure switches in the auto-trans, but only one will generate a unique fault code clearly stating that it is a auto trans pressure switch issue. The second one, and the one that I believe we are all having problems with, trips the fault code for the Shift Solenoid A, fires up the AT light on the dash, and puts the car into "Limp Home Mode". This obviously makes diagnosing the issue a bit harder, especially when this type of code is not stored when the vehicle is turned off.

So, right now I have a new pressure switch in my glove box waiting for me to get annoyed enough with the car want to put it in. The switch cost me NZ$150 ex Japan, and the auto-electrician tells me that it is buried inside the trans somewhere, and they will need the help of a transmission specialist to get to it.

I have attached the wiring diagram and circled the component I think is the source of our problems.

Your thoughts?

InspectorGadget

Has anybody got an update on this or any more recent experiences? Any feedback appreciated.

[V28VX37]

Apologies for digging up an old thread. I've had the same 'stuck in 3rd' problem occasionally, pretty much follows the same pattern as described here by multiple people, and has so far always been resolved by restarting the car.

I want to get the box checked and serviced by someone who is familiar with the R34 Tiptronics and knows what they're doing. Can anyone recommend a shop in Melbourne inner suburbs? Thanks guys.

Forgot: Also considering putting in a shift kit and trans cooler so if the shop has experience in these, even better. Cheers.

Edited January 30, 2013 by V28VX37