How to diagnose the Torque Converter failure....

[DHall1]

As the title states. More and more we are all facing this issue.

Knowing and understanding how exactly the TC works and how to spot potential failures before the famous check engine light...may help some of us.

17125 - Torque Converter Clutch: Stuck OFF / No Power being transferred
P0741 - 003 - Mechanical Failure - MIL ON

So here is my thinking.

Normally, when your driving down the hwy at 75mph....the TC clutch is locked. Then if you depress the brake pedal...that should signal the TCU to "unlock" the TC clutch. That said, you should notice a very slight increase in engine rpm......because the TC clutch should unlock and the rpm tick up.

So if that is true....we should be able to drive down the road at a steady 75 holding the gas and then tap the brake. Clutch should unlock and rpm rise just alittle.

If the failure is the TC clutch stuck "unlocked" then if you have a potential failure...you will not see a rpm rise when you tap the brake because your TC clutch never locked up.

[AudiRS4ever]

This is really helpful. Thanks Dave.

[RS6-4dr911]

You may be right but I'll bet 1/2 of one of your chicken dinners you're not, based simply on the fact that when I slow for a stop sign, the cars feels just like a manual gearbox as far as engine braking goes. Only when it gets to a few miles per hour does it seem like the clutch disengages.

Anyone with actual knowledge want to set one of us straight?

[V8weight]

Here's my experience when my torque converter failed. Going down the freeway at 70mph, the car should be running 2400rpm in lockup. As I accelerated onto the free way and the car shifted to 5th, I could tell that the converter wasn't locking up. It was running 2600rpm at 70mph. If I messed with it enough I could sometimes get it to go into lockup, like lifting off and reapplying the gas, or using the paddles to downshift to 4th and back up to 5th. That worked for about 2 days then it wouldn't lock up at all. So in a nut shell, you'll notice about a 200rpm increase at highway speeds.

[DHall1]

We are in the early stages of troubleshooting but I see chicken dinners in my future.

You could be feeling the actual downshift and not the TCC unlocking.

"Normally" as I said above...its the depression of the brake pedal that "unlocks" the TCC.

RS6's are not normal vehicles. I need to run a Vag data log to see. Anyone know the log block for TCC?


You may be right but I'll bet 1/2 of one of your chicken dinners you're not, based simply on the fact that when I slow for a stop sign, the cars feels just like a manual gearbox as far as engine braking goes. Only when it gets to a few miles per hour does it seem like the clutch disengages.

Anyone with actual knowledge want to set one of us straight?

[DHall1]

Bingo

There you go.

"If" the failue of the TCC means that the TCC will no longer go into lockup..."then" we could be on to something.




Here's my experience when my torque converter failed. Going down the freeway at 70mph, the car should be running 2400rpm in lockup. As I accelerated onto the free way and the car shifted to 5th, I could tell that the converter wasn't locking up. It was running 2600rpm at 70mph. If I messed with it enough I could sometimes get it to go into lockup, like lifting off and reapplying the gas, or using the paddles to downshift to 4th and back up to 5th. That worked for about 2 days then it wouldn't lock up at all. So in a nut shell, you'll notice about a 200rpm increase at highway speeds.

[p3u]

Tozo, care to chime in? :mech:

[TozoM8]

17125 could be a stuck valve in the valve body. There are 5 mechanical valves and 1 electronic pressure control valve that controls TC lockup. If any of those stuck because debris in the fluid it would trigger that code. It is fixable by cleaning the VB. However if you had this problem for a long time partially open TC burns up the fluid make it black and it also burns up the TC clutch. Unfortunately 17125 doesn't mean the TC is open, it means the TC is not able to close but trying so it is almost locked but slipping.

[p3u]

17125 could be a stuck valve in the valve body. There are 5 mechanical valves and 1 electronic pressure control valve that controls TC lockup. If any of those stuck because debris in the fluid it would trigger that code. It is fixable by cleaning the VB. However if you had this problem for a long time open TC burns up the fluid make it black and it also burns up the TC clutch. Unfortunately 17125 doesn't mean the TC is open, it means the TC is not able to close but trying so it is almost locked but slipping.

Better answer the guessing lol.

[DHall1]

Yes I follow your path.

What about the brake pedal application while holding speed at say 75mph. Should it "unlock" the TC?

I doubt this particular code in our cars is a problem with the valve body as 99% of the time the TC replacement solves the problem and owners move on....the valve bodies are never touched. I do understand how dislodged debris can cause a problem in the VB.....but dont see how it could cause the main problem of the code and failed TC. The TC is a known problem and Audi has an updated unit.

That said, I do follow the path of burnt fluid from the TC clutch slipping. So to recap, if your TC clutch is slipping....your burning up your fluid.


17125 could be a stuck valve in the valve body. There are 5 mechanical valves and 1 electronic pressure control valve that controls TC lockup. If any of those stuck because debris in the fluid it would trigger that code. It is fixable by cleaning the VB. However if you had this problem for a long time partially open TC burns up the fluid make it black and it also burns up the TC clutch. Unfortunately 17125 doesn't mean the TC is open, it means the TC is not able to close but trying so it is almost locked but slipping.

[DHall1]

Check your spelling.

And I dont see an answer to the first question.

And I also dont see whats so funny about posting a question and coming up with a process to test these things.

LOL



Better answer the guessing lol.

[TozoM8]

Here is a picture from last week. It's low quality, but you can see a big pile of debris on the middle of the VB. If you don't clean the VB just put new fluid and filter the increased flow (because of the clean filter) could flush all that debris into that hole next to it and it will get into the valves. That's why I don't recommend fluid/filter change on high mileage cars.
http://audipages.com/tozo/IMAG0129.jpg

[TozoM8]

Here is another pic that shows how much stuff is right next to a small hole ready to block the flow.
<img src="http://audipages.com/tozo/DSCN1730.JPG">

[hahnmgh63]

I don't see how someone could let their fluid get that bad unless it is because of a bad TQ burning the fluid in a short time. Nobody should let their RS6 get to high mileage without a fluid change or two......or three.

[p3u]

Check your spelling.

And I dont see an answer to the first question.

And I also dont see whats so funny about posting a question and coming up with a process to test these things.

LOL

Jeesh! Don't take that the wrong way, just responding to what you wrote as it was speculation, and wanted tozo to reply since he is an expert at this sort of thing. No point second guessing when somone on here knows the answer...

[TozoM8]

That black stuff is burnt clutch material from the TC.

[DHall1]

What you call "speculation" on my part....was more a question and answer process from my perspective. I thought you were an engineer? Dont engineers pose questions to problems and try to backward "engineer" the design and identify potential early warning signs?

How many threads have you started over the last year asking the same question over and over and over again? I dont think you would be happy with members giving you smart alec responses and then laughing out loud at you? Sorry that is how I feel.

I dont doubt the existence of said debris in some transmissions. That was not the direction of this thread. The direction of this thread was to ID a potental early warning sign. (A question still not answered by your expert witness)


Jeesh! Don't take that the wrong way, just responding to what you wrote as it was speculation, and wanted tozo to reply since he is an expert at this sort of thing. No point second guessing when somone on here knows the answer...

[TozoM8]

To try to answer your question. I guess you can test it that way or just try to accelerate slowly. If your rpm goes up but your speed does not increase linear with the rpm it is open/regulating. There is no early sign. That fault is 2 cycle code. If it happens twice you have a code and CEL.

[p3u]

I dont think you would be happy with members giving you smart alec responses and then laughing out loud at you? Sorry that is how I feel.




If your that upset over what I wrote I apologize, not my intention. I have asked for your advice on multiple occassions, because I know you are knowledgeable and respect your opinion, so don't look at it like I'm trying to belittle you when I'm not.

[DHall1]

Thanks for your input on these things. Yes, its a problem area that can really cause a pain in butt for some members.

I really just wanted to pin down a test process to verify that the TC clutch is working or if the TC clutch is slipping and not holding the power or if the TC is not even going into lockup at all.

I can test a couple of cars with the Vag and get back to everyone.


To try to answer your question. I guess you can test it that way or just try to accelerate slowly. If your rpm goes up but your speed does not increase linear with the rpm it is open/regulating. There is no early sign. That fault is 2 cycle code. If it happens twice you have a code and CEL.

[TozoM8]

Two more things to ad. Faulty brake light switch can cause TC problem. When you see people driving with the brake light on (broken switch or they resting their foot on the pedal) that is a fast way to the transmission shop.

[DHall1]

No worries. Its funny because I dont even have transmission problems and I still work on algorithm trees just too ID the problem sooner. Why? So many new members are buying these things with blown transmissions and thats no fun. And I want to buy my 2nd RS6 with a good trans. :hahahehe:

Genxer and Tozo may have something on the fluid. I just think the TC clutch material was not strong enough for the car. I dont know if fluid will patch that situation. It cant hurt to change it more often. Its also good to have a trans expert on the forum. I hope he sticks around. Anyone with a 6speed S8 is a real gear head.


If your that upset over what I wrote I apologize, not my intention. I have asked for your advice on multiple occassions, because I know you are knowledgeable and respect your opinion, so don't look at it like I'm trying to belittle you when I'm not.

[terrytcl]

Two more things to ad. Faulty brake light switch can cause TC problem. When you see people driving with the brake light on (broken switch or they resting their foot on the pedal) that is a fast way to the transmission shop.


if this is the case, why not change out the part more frequently instead of waiting for it to fail?

i know the replacement of this switch was covered in another thread, but it maybe something to consider after every 15k miles (or something like that)

????

[terrytcl]

tozo,

in regards to the clutch material clogging up the valve body, would it make sense to have the valve body removed and cleaned if you start to feel any slipping?

or would it by then be a mood point since you've probably burnt up your clutch plates?

[TozoM8]

I would for sure. Clean the VB, check all the valves if they stuck and put a bottle of red LubeGuard in it.

[terrytcl]

tozo, do you own a shop? perhaps you can rebuild my tranny through my warranty :)
plus, i'm only 15 minutes from you

[TozoM8]

Let me know if you need it fixed. tozoa8 at yahoo dot com

[SteveKen]

. . . So many new members are buying these things with blown transmissions and thats no fun . . .

Sorry for the semi thread jack, but the 01E is still an option for the adventuresome. I'm still looking for someone that wants to try this on their car or point me in the direction of a car with a bad trans or engine that I can buy.

After I fine tune the ECU work on my 6 speed S6, I'm going to devote more time, money and effort to this.

[GEN XER]

Here is a picture from last week. It's low quality, but you can see a big pile of debris on the middle of the VB. If you don't clean the VB just put new fluid and filter the increased flow (because of the clean filter) could flush all that debris into that hole next to it and it will get into the valves. That's why I don't recommend fluid/filter change on high mileage cars.


What do you consider high mileage?

[GEN XER]

[QUOT
E=GEN XER;175938]What do you consider high mileage?[/QUOTE]

Never mind you said 70-80k in my Tranny Fluid thread. Wow I'm at 69k right now. I don't think the previous owner had the fluid changed so I better get on it.

[V8weight]

I have a couple of things to input here since everybody's doing it. Our torque converter is indeed an updated part, but nothing has been done to actually update the clutch. Rather they have addressed the seals (one lip seal on the input shaft, and 2 o-rings on the piston that actuates pressure on the clutches) that eventually fail and bleed off pressure needed to apply clamping loads to the clutch. This is why our TC's fail, the seals fail, loss of pressure, loss of clamping load on the clutches, slipping starts, torque converter is toast in a matter of miles. All the fluid changes in the world aren't going to change the fact that if you're on the original TC, these seals are slowly pushing themselves out and loosing pressure.

Second, I support GenXer's offering for a replacement oil. I've been impressed with his offerings to the board thus far and will gladly follow any future advice that he has to offer. But I need to see more data on the new trans oil, which I'm sure he can provide. I'll admit that I'm not an expert on this, but there's more to this than just dumping synthetic fluid in and giving ourselves a pat on the back. While the benefits of synthetic trans fluid include more consistant viscosity and line pressures at both lower and higher temps, what about the friction modifiers that allow adequate "traction" between all of the steelie's and friction plates within the transmission?
I'm all about switching to a better fluid that adds better protection to the lubricated parts of the trans, I just want to make sure that I have adequate friction for the clutches and bands as well.

[4everRS]

That is a very good point Pat. It is very common in motorcycles with wet clutches to have this happen. When you dump synthetic oil that is not made for a bike, the plates will not have enouph friction to hold anymore. You will usually notice a loud ticking from where the clutch is located first. I realize that our trannies are very different than a cycle, but Pat has a valid concern. Gen Xer, could you or the supplier address this point?

[DHall1]

+1

Clearly Tozo does lots of Audi transmissions and he uses a synthetic on complete refill. It must work.

I mentioned in another thread if you want to change the oil to this BYD stuff or some other synthetic thats fine. But, you better do a complete flush by pulling the cooler return line and getting all of the old stuff out. Again, I think this will be fine.

Lastly, as Pat points out.....if there is an updated TC. Its updated for a reason. The seals as he mentions are just on borrowed time before they fail on all of us. You cant get around it no matter what fluid you use.

For me at 30k. I will go ahead and use the Audi fluid at 35 when Pat comes down to AZ and we have the RS6 club timing belt party at my house. Drain and refill with the Audi fluid and I will be fine. I will not bother with a complete flush and refill with some synthetic fluid. My TC will burn up some day and Fidelity will be happy to replace the trans and TC. :hahahehe:


I have a couple of things to input here since everybody's doing it. Our torque converter is indeed an updated part, but nothing has been done to actually update the clutch. Rather they have addressed the seals (one lip seal on the input shaft, and 2 o-rings on the piston that actuates pressure on the clutches) that eventually fail and bleed off pressure needed to apply clamping loads to the clutch. This is why our TC's fail, the seals fail, loss of pressure, loss of clamping load on the clutches, slipping starts, torque converter is toast in a matter of miles. All the fluid changes in the world aren't going to change the fact that if you're on the original TC, these seals are slowly pushing themselves out and loosing pressure.

Second, I support GenXer's offering for a replacement oil. I've been impressed with his offerings to the board thus far and will gladly follow any future advice that he has to offer. But I need to see more data on the new trans oil, which I'm sure he can provide. I'll admit that I'm not an expert on this, but there's more to this than just dumping synthetic fluid in and giving ourselves a pat on the back. While the benefits of synthetic trans fluid include more consistant viscosity and line pressures at both lower and higher temps, what about the friction modifiers that allow adequate "traction" between all of the steelie's and friction plates within the transmission?
I'm all about switching to a better fluid that adds better protection to the lubricated parts of the trans, I just want to make sure that I have adequate friction for the clutches and bands as well.

[GEN XER]

That is a very good point Pat. It is very common in motorcycles with wet clutches to have this happen. When you dump synthetic oil that is not made for a bike, the plates will not have enouph friction to hold anymore. You will usually notice a loud ticking from where the clutch is located first. I realize that our trannies are very different than a cycle, but Pat has a valid concern. Gen Xer, could you or the supplier address this point?

Which point? The seals, TC parts or the fluids ability to help with this?

[GEN XER]

This is BND's respnse to a question about there tranny oil and software management.

"That is only if you change the composition of the fluids. I made a copy of the fluid but changed some of the characteristics of the fluid that were shortcomings and added ultra high heat durability that will greatly resist the shearing that occurs due to high rpm, high heat, and internal friction. Reduce the friction between the gears and main shaft and you reduce the heat and increase the power transfer etc".



That is a very good point Pat. It is very common in motorcycles with wet clutches to have this happen. When you dump synthetic oil that is not made for a bike, the plates will not have enouph friction to hold anymore. You will usually notice a loud ticking from where the clutch is located first. I realize that our trannies are very different than a cycle, but Pat has a valid concern. Gen Xer, could you or the supplier address this point?

[GEN XER]

Dave, Tozo

Is there a link you can point me to for instructions on flushing the system? Does the front clip have to come of to get to the oil cooler? How do you pump fluid through the TC? This it turning into a more than just changing the fluid and filter.




+1

Clearly Tozo does lots
of Audi transmissions and he uses a synthetic on complete refill. It must work.

I mentioned in another thread if you want to change the oil to this BYD stuff or some other synthetic thats fine. But, you better do a complete flush by pulling the cooler return line and getting all of the old stuff out. Again, I think this will be fine.

Lastly, as Pat points out.....if there is an updated TC. Its updated for a reason. The seals as he mentions are just on borrowed time before they fail on all of us. You cant get around it no matter what fluid you use.

For me at 30k. I will go ahead and use the Audi fluid at 35 when Pat comes down to AZ and we have the RS6 club timing belt party at my house. Drain and refill with the Audi fluid and I will be fine. I will not bother with a complete flush and refill with some synthetic fluid. My TC will burn up some day and Fidelity will be happy to replace the trans and TC. :hahahehe:

[TozoM8]

I DO NOT recommend flushing the system. If you have built up debris in the valve body the flush could brake it loose and block the orifices in the valve body. I would just change the fluid (drain it overnight) 8qt of Mobil 1 Mercon V $65. If you do it one more time in a couple weeks, you will have new synthetic fluid for $130+filter. This was you don't do any drastic changes.

[GEN XER]

I DO NOT recommend flushing the system. If you have built up debris in the valve body the flush could brake it loose and block the orifices in the valve body. I would just change the fluid (drain it overnight) 8qt of Mobil 1 Mercon V $65. If you do it one more time in a couple weeks, you will have new synthetic fluid for $130+filter. This was you don't do any drastic changes.

How about the filter and oil cooler, you would not change or flush them either?

[TozoM8]

You replace the filter and the cooler will be flushed when you refill the tranny.

[GEN XER]

You replace the filter and the cooler will be flushed when you refill the tranny.

You sound like the Audi Tech who is doing the work on my car. He told me the exact same thing, but others would say not to run the old fluid back through the system, because it has contaminates in it, but a new filter would catch most of that right.

[Shoppinit]

DHall's method is pretty good. I would like to give some more weight to it by describing my experiences with determining that my TC was OK.

I wanted to make sure that my TC was locking up properly. I found that the best way was to log the autotrans module, blocks 1, 3 and 7. This way you can see the input and output speeds from the box (if they're the same, then the TC lockup clutch is functioning). Well, have a look at the logs, you'll get the picture. Pretty much all the information you need is there.

http://img690.imageshack.us/img690/6650/autotranslog.jpg

[DHall1]

^^

I do see those chicken dinners.

:deal:


You may be right but I'll bet 1/2 of one of your chicken dinners you're not, based simply on the fact that when I slow for a stop sign, the cars feels just like a manual gearbox as far as engine braking goes. Only when it gets to a few miles per hour does it seem like the clutch disengages.

Anyone with actual knowledge want to set one of us straight?

[V8weight]

This also shows that we have about a 1700rpm stall speed. Lame
Edit: Nevermind, I was way off track on that one.

[TozoM8]

The highlighted areas are not the ones that important. You need to look engine speed- input speed-TC slip speed. The input-output would show you if one of the clutches slipping. The TC is between the engine and the input speed sensor. The TC open-regulating-closed is a command, not a reading. the TC slip speed is a calculated number between the engine and the input speed.

[TozoM8]

Apply brake. Step on the gas and see how high the rpm goes. The stall speed when the engine is not able to rev any higher. It is 1800 on the A/S8.

[V8weight]

Oh I see, I've edited my post accordingly.

[RS6NZ]

Excuse the slightly long post....

Ever since I've read this thread I've been monitoring the torque converter clutch lock-up by watching engine revs at a constant speed on a particular stretch of slight uphill road that I travel every day. My RS6 has done 151,000 km on original tranny so it must be getting into the danger zone.

About a week ago I noticed that the revs jumped by 200 or so going up the road (100 kph = 2050 rpm normally), and I even fancy I felt a slight vibration or tremor while it happened. Once onto level road, the revs dropped back down to 2050 (and the vibe stopped) as the clutch locked up again.

This was just a once-off, next day and every day since, it's been back to normal revs going up that stretch. My VAG-COM arrived on Friday, and I scanned for fault codes over the weekend, and guess what - 17125 was there.... (interestingly no CEL illuminated however). I'll log the transmission blocks later today, just to check the engine revs/input revs ratio for slip and confirm the clutch is still locking up.

So, seems intermittent at the moment (if a once-off is intermittent), but is it the onset of torque converter failure (through the seal failure that seems to be the underlying weakness in these) or is it the debris blocked valve problem also discussed in this and other threads (or are they both the same thing - the seals start to give way, cause slip in the TC clutch which causes the debris that clog the system)???

As it happens the car is in for service on Monday (and to replace one of those other Audi bugbears, the leaky auxiliary coolant pump!), and I'm going to talk to the tech about doing what TozoM8 suggests - removing the VB and cleaning the debris out, checking the valves that can be checked, and doing a filter change and fluid flush, . BTW, I presume that can all be done from under the car, without dropping the tranny?

Assuming this can be done, I'll then keep on monitoring the situation - presumably if the code comes back, its new torque converter time, if not....then fingers crossed!

[TozoM8]

If your TC is going bad nothing you can do about it, but if you just low on fluid it would result in a "hickup". Going uphill and accelerating would splash all the fluid to the back of the trans and the filter's pickup pipe could suck air in for a moment.

[Aronis]

I have been logging block 7 for the past few days. I am still trying to learn what the data means. I noticed the log show above has an offset in time for each block measured so the data does not exactly line up for time.

My log showed that as the TCC moved from CLOSED to open, some times the amps on the Solenoid were at about 0.4 as opposed to the .744 which it shows when it's closed. I am not sure if this means the TCC is openning and has not registered as fully open or as Torq.Conv.Reg at the exact moment the solenoid amps started to drop. But if the TCC is getting stuck closed, and the solenoid is changing it' state that would make sense that it would trigger the error message.

Today the 17125 showed again, but this time the failure line says INTERMITTENT.

I would love to know at what point the CEL will light!?!?!? I don't think the shop will fix the torque converter or even investigate until the CEL is lit.

When I drove into the hospital tonight I was looking at the block 7 data, and I never saw the TC closed!?!? Highway at 70 for 10 miles on cruise control. I'll have to check the log later, but it appears my TCC never closed during that trip.

Mike

[4everRS]

Mike, just guessing here but how's the fluid level of your tranny? Have you ever noticed leaking? Thinking that if there is not enough fluid, pressure is not building enough to fully engage TC. Try replacing fluid and filter first, then see if it does the same stuff. Like I said, just guessing. This may also have something to do with your temp range I see in another thread. If nothing else, you will see how the old fluid looks and if there is crap floating around, your TC is f@#%ed, and fix it before the tranny is shot.

[Aronis]

Yes, had new seal on tranny at about 75000 miles. No evidence of a leak since.

I know the TC is going based on miles but I'd still like to know more about the diagnostics.

How many people with shot TC just happened to catch the error code before a CEL showed?? How long before the CEL will light?

If I show up with the car and the log and an error code without cel I'd be sent back home. "come back when the cel is on"

[DHall1]

Yes, had new seal on tranny at about 75000 miles. No evidence of a leak since.

I know the TC is going based on miles but I'd still like to know more about the diagnostics.

How many people with shot TC just happened to catch the error code before a CEL showed?? How long before the CEL will light?

If I show up with the car and the log and an error code without cel I'd be sent back home. "come back when the cel is on"

Mike,

If your tc is going bad then I can fry it in one test drive. Take the car out on a rural hwy. Hold 55 then roll into throttle. Repeat 10 times. Hold 55 then roll into throttle. Boom

[Aronis]

That's contrary to my service department managers view.

I caught my warning message very early

The TCU program monitors for specific sequence of errors before the CEL comes on.

He said drive it normally. I'm taking it in on Tuesday for a transmission fluid change and they will try to get the warranty company to authorize a TC replacement. They have done a "good number" of A6 TC replacements and have not seen a transmission failure due to the TC failure.

They (Audi) do not routinely scan cars at routine service "looking" for early error messages. They only respond to CEL light activations which are specifically coded to warn of a "real" problem.

Of course I think that is foolish as an early detection of a coming problem makes MUCH more sense. If the early warning is a false alarm so be it. Put the cost of early warning diagnostics to the owner. Those who want to pay for a premature check should have that option n

[johnnie27]

Mike,

If your tc is going bad then I can fry it in one test drive. Take the car out on a rural hwy. Hold 55 then roll into throttle. Repeat 10 times. Hold 55 then roll into throttle. Boom

Mr Hall, i just tried this for all this TC talk has made me think about something i never questioned... anyhow when it comes to this car you seem to be the most switched on bloke out there, ..but now with all those waves a torque i feel car sick....everytime i rolled on barrrppppppp...but i was a good way to check if its grabbing and holding the gear! it is raining here... RS6 is truley a great car with the ESP off.... she will steps out beautifully..all she really needs is a front LSD.. johnnie

[DHall1]

IMHO the trans fluid change is a complete waste of time. If the tc clutch is going....the clutch material is already toast.....fluid change does nothing.

I would continue to drive the car and see what happens. We should be talking about a matter of days.

Driving at 55 then make sure the tc is locked. Then load that tc clutch by gently rolling into the throttle. If its going to slip...then the above procedure will make it happen. period


That's contrary to my service department managers view.

I caught my warning message very early

The TCU program monitors for specific sequence of errors before the CEL comes on.

He said drive it normally. I'm taking it in on Tuesday for a transmission fluid change and they will try to get the warranty company to authorize a TC replacement. They have done a "good number" of A6 TC replacements and have not seen a transmission failure due to the TC failure.

They (Audi) do not routinely scan cars at routine service "looking" for early error messages. They only respond to CEL light activations which are specifically coded to warn of a "real" problem.

Of course I think that is foolish as an early detection of a coming problem makes MUCH more sense. If the early warning is a false alarm so be it. Put the cost of early warning diagnostics to the owner. Those who want to pay for a premature check should have that option n

[Aronis]

The fluid change is for two reasons. Log the error message officially with Audi and warranty co. And to be certain it is not low on fluid!!

I know new fluid will not heal the TC but remember there's a well documented list of reasons why that code is tripped. I do not yet fully understand the programming. I noticed that my TCC remained open on the highway but the solenoid numbers were consistent with the open state. It was not the the solenoid amps was at .744 and the TCC was stuck open. Why would the TCU give up on trying to close the TCC if the conditions called for it and not apply current to the solenoid?? So I looked at the logs again and never did I see the solenoid power on and the TCC not closed.

Mike

[DHall1]

I can deal with that logic. Interesting the TCC is not locking up.




The fluid change is for two reasons. Log the error message officially with Audi and warranty co. And to be certain it is not low on fluid!!

I know new fluid will not heal the TC but remember there's a well documented list of reasons why that code is tripped. I do not yet fully understand the programming. I noticed that my TCC remained open on the highway but the solenoid numbers were consistent with the open state. It was not the the solenoid amps was at .744 and the TCC was stuck open. Why would the TCU give up on trying to close the TCC if the conditions called for it and not apply current to the solenoid?? So I looked at the logs again and never did I see the solenoid power on and the TCC not closed.

Mike

[twinsteve]

I just did my first scan (car has 44k miles, but I bought it about a month ago) and 17125 and 17095 (Trans Fluid Temp Sensor -- Mechanical Failure, Intermittent) came up....are the two in any way related??

[V8weight]

I just did my first scan (car has 44k miles, but I bought it about a month ago) and 17125 and 17095 (Trans Fluid Temp Sensor -- Mechanical Failure, Intermittent) came up....are the two in any way related??
If by related you mean one will fix the other, I don't believe so.

[twinsteve]

ha..thx..didn't think so, but I wanted to cash in one of my "new guy gets to ask a dumb question" chips....read all the posts/threads on TC/17125 code and trying to decide how freaked out to be

[TozoM8]

One could cause the other. The TC only locks if the fluid temp is above 30Celsius. Faulty sensor could keep it open, but the engine temp is normal so it could trigger the fault. The trans fluid sensor is in the valve body wiring harness.

[DHall1]

Congrats your torque converter is shot.

Nope, owners dont trade their cars in when they find out the trans is toast.

[twinsteve]

One could cause the other. The TC only locks if the fluid temp is above 30Celsius. Faulty sensor could keep it open, but the engine temp is normal so it could trigger the fault. The trans fluid sensor is in the valve body wiring harness.

So, is replacing the temp sensor and also doing new trans fluid/filter just a total waste of money, or is there some chance the TC is actually fine, but the code is being thrown due to the other issues? I need to get on the road today and do some of the "testing" talked about in other threads to test TC

[DHall1]

Best way to test the TC is with the Vag Com hooked up and monitor the TCC trigger.

Most likely the TC is starting to go bad. If you just got the car and planned on a warranty anyways better get it asap. You will have to wait 30 to 60 days before a claim such as this so drive the car very little.

[TozoM8]

You need to replace the temp sensor anyway, so you should do it and see if it fixes it. You will have to drop the pan to do it so clean the TCC solenoid while you are in there. It is the second from the left (driver's side). You need to remove the clamp that holds all of them in and just pull the TCC solenoid out to clean it.

[CornersWell]

I just did my first scan (car has 44k miles, but I bought it about a month ago) and 17125 and 17095 (Trans Fluid Temp Sensor -- Mechanical Failure, Intermittent) came up....are the two in any way related??

Our cars must be on the SAME cycle! The same codes were thrown on 9/21/10. WTF? My warranty company is going to be PISSED. And, we still haven't figured out the overage for the alternator replacement and control arms, yet. Another claim? Already? These cars are FRAGILE, and I'm getting the sense they're pretty poorly engineered.

CW

[MaxRS6]

Our cars must be on the SAME cycle! The same codes were thrown on 9/21/10. WTF? My warranty company is going to be PISSED. And, we still haven't figured out the overage for the alternator replacement and control arms, yet. Another claim? Already? These cars are FRAGILE, and I'm getting the sense they're pretty poorly engineered.

CW

I say who gives a p*ss what the warranty company likes/dislikes. You have paid for your coverage and they are obligated to pay the coverered items. They placed the bet and the roulette wheel has spun. However; it is a pain in the a$$ to have the car in the shop being repaired (I speak from plenty of experience as my car is scheduled to go back to its' second home again Tuesday). This time I have an engine bracket, and a flippin annyoing dammmmm brake pad sensor light that keeps lighting up (the sensors are not even connected) and the tech has yet to find a resolution. It is not a major items but quite annoying have a false sensor light up the dash.

I feel your pain as I went through the tranny issue about 20K miles ago and I'm praying to the car gods it will hold up for the remaining time I have with her.

Good luck with a resolution!

[CornersWell]

Yes, I agree. They took my premium, so they're on the hook. That's the breaks. Problem is that they have ways of torturing you...

CW

[DHall1]

RS6 fragile? I know it may seem that way at times but remember folks. We could be driving a GM that literally starts falling apart at 30k.

The TC problem is a known failure point in the Audi vehicles but for the most part the RS6 is a solid performer and rock solid platform. Just as Pat who is putting down some crazy hp and torque numbers for just a stage 2ish modded driveline.

And +2 on the warranty company. Piss on them.

[CornersWell]

Is the A6/RS6 platform that good? I mean, torque converters have been around a while, too. And, the DRC wasn't exactly ready for prime time. And, the control arms seem like they were designed by someone who doesn't understand wear and tear. Just saying that of the RS6 owner group, we have a HIGH number of failures with common items. But, I agree that the 4.2L V8 is rock-solid.

CW

[CornersWell]

Confirmed this morning that I need a new TC. Couple of options:

1. Rebuild existing. See ImportPerformanceTrans.com. Rebuild is $699. GUARANTEED never to go out again. Currently being used in a local RS6 with 650 RWHP for more than 10k miles. Driven hard. NO problems.

2. Aftermarket. See aceconverter.com. RS6 model is $424.50

3. Audi Upgraded OEM. Don't know how much, but it ain't cheap!

Any thoughts or experience with any of these?

Thanks,

CW

[MaxRS6]

I've had experience with IPT. Ty (the IPT rep I dealt with during my repair) is not a man of his word and I have multiple emails to support my claims. With that said, I have had the IPT tranny in for about 20K and it has performed well to date. However; I would not trust one thing that Ty states or claims.

My less than .03 worth. I'd be happy to discuss further with you if you would like further information.

Good luck with a repair!

[CornersWell]

Certainly not a glowing endorsement, but I actually wouldn't be the one dealing with IPT. The independent service shop would be. And, they've dealt with them before. Frankly, $699 is high, relative to the $424. But, it may be worth it. The rebuild would take the car out of service for a week, at least. The aftermarket converter or Audi's upgrade would be a day or two only.

CW

[CornersWell]

So, the warranty company will pay for the re-build and to pull the transmission and to reinstall it. They won't pay for the shipping ($100) or the transmission service (roughly $450 in parts and labor for the fluid and filter change). I'm good with that and approved it. It's going to IPT. Their problem!

CW

[MaxRS6]

Sounds like a win! Enjoy the new tranny and I wish you a speedy recovery.

[twinsteve]

Got diagnosis today from dealer....bad TC and bad passenger side EGT sensor....Fidelity covering both....oh, and my sunroof switch was bad too :)

[V8weight]

Got diagnosis today from dealer....bad TC and bad passenger side EGT sensor....Fidelity covering both....oh, and my sunroof switch was bad too :)
Make sure they are replacing both EGT sensors, as there is a TSB stating that they must be replaced in pairs.

[twinsteve]

Make sure they are replacing both EGT sensors, as there is a TSB stating that they must be replaced in pairs.

thx...wasn't aware of that

[twinsteve]

got a 2010 Q5 from the dealer as loaner....not too shabby at all..sadly, the kids are so entranced by the length-of-the-car sunroof it has they are begging for me to ditch the RS6 and keep the Q5...sigh