Solved - Problems with Automatic Transmission Touareg 5R

Hello,
We use a test aircraft from VW (not road-legal) as a LEPO (for towing and flying) in our glider club. Last week, it simply stopped while pulling the towing rope. Then it could only be moved in reverse.
After some time, he started moving forward again, but subjectively with a weak stride, and when the selector lever was operated, there were strong jolts.

I have read out the error codes with the following result:

Address 02: Transmission Label file: RKS\09D-927-750.lbl
Part Number: 09D 927 750 CL HW: 09D 927 750 CL
Part and/or Version: AL 750 6A 1022
Encoding: 0004456
Operating Number: WSC 31414 790 00001
3 errors found:

00266 - Solenoid Valve 5 (N92)
009 - Interruption/Short Circuit to Ground - Sporadic - Warning Light ON
00453 - Function Limitation Due to Overheating
000 - - - Sporadisch
00641 - ATF Temperature
001 - Upper limit exceeded - Sporadically

I have absolutely no experience with automatic transmissions. Can anyone give me a tip on what to do?

Flight Diesel

Here is the information about the solenoid:

/viewtopic.php?t=923

And regarding the other errors:
I suspect that the Touareg has an oil/air cooler for the automatic transmission oil.
It is likely that when towing gliders, it is also necessary to accelerate quickly, using the "kickdown" function.
Then slow down again and return to the starting point.
This is not designed for automation. Don't be fooled by the temperatures of the last few days
In this case, and if the Touareg only has an air-oil cooler, it is advisable to install an additional fan, as is often the case with vehicles designed for tropical climates or with towing equipment.

Tagessuppe wrote:

It is likely that when towing gliders, it is also necessary to accelerate quickly, using the "kickdown" function. Then slow down again and return to the starting point.

The glider is lifted into the air by a wind, while Lepo only pulls the ropes out.

I agree with you regarding the conditions at the airfield: cars often have problems there. Here in Braunschweig, a Touran with DSG transmission is used. When pulling the aircraft for takeoff, it is done at a very slow pace. The car's automatic system cannot cope with this: after the acceleration, the engine almost stalls, the control system automatically increases the throttle, and the driver brakes because the car becomes too fast. This does not correspond to the planned everyday conditions....

There's a much better old W123 diesel truck, especially in terms of durability.

Is something off-topic, but I wanted to get it off my chest

jarobaldu wrote:

There's a much better old W123 diesel truck, especially in terms of durability.

Okay, that's correct, except for the lack of performance
A friend had a 300D
With that, we dragged the trailer until the coupling started to smoke.
But it always worked.

I think the sudden jerk when pulling the aircraft is definitely the worst thing for the automatic transmission.
Even worse with GDPR!
In my Lupo with a "Ruckomatik" transmission, the brake pressure switch was faulty, which caused the clutch to slip constantly when the car was stationary.
Of course, this also applies in Jordan

After our neighbor's club has been successfully operating two Q8 units for the same application profile for about 3 years, we believed that the Automatic-Touareg was the perfect solution. Of course, the slipping is a problem; where should the heat go? But can you break it with this?
It is rumored that some "specialists" within the club have been setting the selector lever to "D" (Drive) even before the actual voting process began.
But can an automatic transmission be ruined within 3000 km (total 67000)?

In the manually shifted Touran, the colleagues completely destroyed the clutch within 14,000 km, with only small pieces remaining in the housing. He drives too fast at full throttle when pulling the plane out, they always let the clutch slip.
When the Touareg's automatic transmission was in "creep" mode, the gear selector was in position S.

Is it worth replacing the magnetic valve on suspicion (fault in the wiring harness after 67,000 km???) or could it be the ATF oil (e.g., contaminated with coolant due to a leaking radiator)? How can I check this? Is there somewhere a repair manual?

Every workshop collapses in despair when the keyword "Touareg automatic transmission" is mentioned, no one wants to touch it.

Quote:

Is it worth replacing the solenoid valve on suspicion?

That magnetic valve would be a whole sliding drawer for 1000€! Whether you want to replace it on suspicion, that's up to you.

I would definitely get rid of the ATF, though.

What is a Q8 and doesn't the Touareg have a standard gearbox?

Q8 is the corresponding SUV from Audi. I expected that, apart from the V6 TDI, it would have similar technology (similar automatic transmission) to the Touareg, instead of the R5. I would have expected that if the Q8 could handle this type of operation, the Touareg would also be able to.

I think you might have made a mistake there. The equivalent of the Audi Touareg is the Q7.

And Jet Fuel:
How about the ATF cooling now?
Water or air?

I haven't checked if there's water or air yet - I'm still looking for a repair guide. But yesterday, I re-read the fault codes - after the last time, after deleting the error entries, I drove around the airfield for a few minutes without any "stress tests", just a few laps.
Now the error message regarding the solenoid valve (including the warning light) was back.
Therefore, I am focusing on this. Maybe I'll be able to find a valve to try out.

I've since done some research and, after studying the VW 367 self-study program and further tests with VCDS and logging specific data sets (gearbox oil temperature, speed, gear, power consumption of the N92 solenoid valve), I've identified the problem.
1. The gearbox oil cooler is oil-air.
2. It is likely that the N92 solenoid itself is defective. This controls the K1 clutch, which in gears 5 and 6 disconnects the connection between the planetary carrier of the first planetary gear set and the small sun gear of the second. I would argue that, even in the position P, R, N, when the current is around 1 A, a short circuit or a disconnection of a wire should result in an error message.
3. If the clutch doesn't disengage, I believe that both planetary gear sets (S2 and S3) are engaged in the 5th gear. This causes a jerk. What then happens is not entirely clear to me, because the transmission then goes into emergency mode and the 5th gear remains in place (this is not entirely clear; normally, emergency mode should engage the 3rd gear, but according to the description, it keeps the 4th, 5th, and 6th gears in place until either the gear lever is set to N or a restart is performed). If the 5th gear remains in place and the clutch K1 doesn't disengage, then both planetary gear sets must be constantly engaged in the 2nd gear, which is obviously not possible. Apparently, the emergency program doesn't work somehow, and then maybe another component fails, or it's actually the 3rd one. Gear engaged and only the display remains at 5.
4. The slow start can be explained by the fact that at least the 3rd... Admitted to the emergency program.
5. The hard shut-off mechanisms explain this by stating that all magnetic valves operate at maximum pressure in the emergency program.
6. The overheating is likely not only a result of the specific airport operations and the high ambient temperatures, but also due to the fact that the mechanics ignored the warning light and disconnected the tow ropes in emergency mode. This then caused the converter coupling to remain permanently open, and at least the 3rd gear was engaged. That means a lot of air trapped in the converter, and therefore a lot of heat.

Actually, only the complete gearbox is available through the VW parts distribution, and costs around €1200 including VAT with us in Austria. Maybe one could find the control valve somewhere on its own.

Does it actually work to reset the gearbox control in order to re-adapt it with VCDS, do I need a password or do I need the original VW Diagroset tester?


P.S. to Turbinchen: Of course, the Q7 - it also has the same automatic transmission as the Touareg!

Hello, again
Now we have managed to donate the €1,100 for the sliding box and have replaced it - we haven't been able to find individual magnetic valves.
We also replaced the oil filter and filled the transmission. In this regard, we made the following compromises compared to the repair service provider, where we obtained the sliding box:
1. We only refilled with 5 liters of fresh oil because it was said that we didn't need more, because there was still so much left in the converter. That's not true, you need about 9 liters, and it all comes out. Therefore, we have refilled with "used" oil that has already experienced the "Function restriction due to overheating" warning.
2. One should clear the fault memory before the filling process - we forgot to do this and only did it afterwards.
3. When filling, the oil temperature must be monitored - it should be around 35°C, as I recall. We won't be far off, but we haven't precisely controlled it.
Now, instead of the message "Magnet valve N91 defective or short circuit against ground," the same message appears with Magnet valve N282. When logging data, it is shown that none of the magnet valves are being energized. The transmission is also immediately in emergency mode after repeatedly deleting the error entries, and when the gear lever is operated, it jerks strongly, and instead of functioning as before, only the 5th gear now works, and only the 3rd gear functions. Forward gear.
I'm fairly confident that the N 282 solenoid valve defect is unlikely – it's new! Perhaps the N91 wasn't broken before??? It also seems unlikely to me that we've made a mistake – there's really nothing to get wrong. Could the error be related to the transmission oil? Should we drain it again, replace the filter, and carefully fill with new ATF according to the instructions? Or does the error actually lie elsewhere (wiring harness, control unit)?
Does anyone in the community have more information?

LG Flight Diesel

Sorry, the initial report did not concern valve N91, but N92!

Flight Diesel

After replacing the shift lever box, the error reappeared after 2 months. I had thoroughly inspected the entire wiring harness and measured everything. Finally, I accidentally discovered the error: One of the contact clamps on the connector at the gear control unit had a tab bent over. That resulted in occasional wobbles.
New clamp installed and the error has been fixed!

Flight Diesel

To protect the engine and transmission, also an update of
Both of these actions can be performed at the store.
Especially facilitates starting, which makes it possible to achieve more torque.
is with.

Then you don't need to step on it quite so hard...