Transmission Code 17125

[ssassc1]

Well I have had this code now for over 12 months

I have been waiting for the gearbox to fail or at least start to play up.

So far nothing. Gearbox is performing well.

So Guess Code 17125 isn't that bad after all? ie Gearbox death sentence?

I contacted the ZF specialist here in Australia and their comments were along the lines of "if its not locking up. Don't worry about it, only down side is your using around 3% more fuel"

I have had the transmission pan pulled and inspected and the oil is perfect and no metal bits.

Am I just lucky?

Cheers, John

[nubcake]

It's related to torque converter, not the internals of gearbox, so it's not a death sentence as such. If anything, a slipping TC should bring less stress to the rest of gearbox. It could go on like this for years if you drive conservatively.
Downsides are: as noted, increased fuel consumption, and greatly reduced performance of the car. Plus, the TC will fail eventually and it won't be pretty.
It's hard to say what to do, because if you replace just the TC, it may kill rest of your transmission mechanicals - if they are on their way out already, but manage to hold so far due to TC itself slipping. So, if you're okay with the performance and fuel consumption, just keep driving, but don't get too far away from home. :)
And it's better to have some $$$ saved up for impending transmission overhaul.

[Bigglezworth]

Well I have had this code now for over 12 months

I have been waiting for the gearbox to fail or at least start to play up.

So far nothing. Gearbox is performing well.

So Guess Code 17125 isn't that bad after all? ie Gearbox death sentence?

I contacted the ZF specialist here in Australia and their comments were along the lines of "if its not locking up. Don't worry about it, only down side is your using around 3% more fuel"

I have had the transmission pan pulled and inspected and the oil is perfect and no metal bits.

Am I just lucky?

Cheers, JohnI drove with a 17125 code for over 5 years. I didn't have drastic performance woes and experienced exactly what I do with my high power Buick that has a non-lock-up convertor - no lock-up at various times... I drove the snot out my car too. Like it was meant to be driven. I've posted it a few times on this forum that it's not a death sentance to throw a 17125 code. Just means the locking portion of the convertor that assists with direct drive through for improved gas mileage isn't working some times. TQ's ar hydraulic in design and 'slip' until their internal components provide fluid coupling to transfer the torque. As long as you have good fluid, your gearbox should be just fine.

The gearbox on the same car I was throwing this error code on for years did finally crap the bed, but you would have to be a good salesman with detailed technical knowledge to convince me that it did so as a result of a convertor that didn't 'lock-up'. I will be tearing that box apart in the new year to see what the internals look like and will report back on my findings.

[mik15]

drove mine for about a year with the same error and honestly i had no idea that something was wrong with the TC if i hadn't read it here and then vagcom it and i am sure it was driven with this error for a long time as the previous owner had no idea either. However, once i knew there was a problem with it i became obsessed of it and starting noticing the delay in locking-up, so i had it replaced. In terms of power loss, i don't really think is noticeable, yeah, if you do a 1/4 mile then you would probably see the difference, otherwise not really, so i'd say the same thing, it is not a death sentence for the gearbox, driven in a sensible way could last a few more years, especially if you get the oil changed regularly.

[DHall1]

Knowing what we know at this point.

If I ever encounter the 17125 in the future...this route is an option. If the rest of the trans is operating and shifts are holding....then run it till your ready to do a full rebuild. Then drive it up to Tozo. ;-)

I would not opt to change the TC only. Ever again.


I drove with a 17125 code for over 5 years. I didn't have drastic performance woes and experienced exactly what I do with my high power Buick that has a non-lock-up convertor - no lock-up at various times... I drove the snot out my car too. Like it was meant to be driven. I've posted it a few times on this forum that it's not a death sentance to throw a 17125 code. Just means the locking portion of the convertor that assists with direct drive through for improved gas mileage isn't working some times. TQ's ar hydraulic in design and 'slip' until their internal components provide fluid coupling to transfer the torque. As long as you have good fluid, your gearbox should be just fine.

The gearbox on the same car I was throwing this error code on for years did finally crap the bed, but you would have to be a good salesman with detailed technical knowledge to convince me that it did so as a result of a convertor that didn't 'lock-up'. I will be tearing that box apart in the new year to see what the internals look like and will report back on my findings.

[ssassc1]

Knowing what we know at this point.

If I ever encounter the 17125 in the future...this route is an option. If the rest of the trans is operating and shifts are holding....then run it till your ready to do a full rebuild. Then drive it up to Tozo. ;-)

I would not opt to change the TC only. Ever again.

Yes - Originally when the 17125 appeared on Vag Com, I was panicking a bit thinking I should pull gearbox and replace the TC. But then I thought.. well wait till gearbox fails and do both?

Thing is, its not failing at all and car still drives great?

[lswing]

Yes - Originally when the 17125 appeared on Vag Com, I was panicking a bit thinking I should pull gearbox and replace the TC. But then I thought.. well wait till gearbox fails and do both?

Thing is, its not failing at all and car still drives great?

My car drove well with the code, really not too noticeable. If you are in 5th, Tip, 50mph, give it full gas and you'll see the rpms jump 500 or so before you move much.

I should have replaced trans first time as it failed 6 months after new TC was put in...

And my new trans failed 8 months after that, but either something failed or I just hammered on it too much...

[volksburgs]

I just purchased mine a few months back and it has 89.5K miles. Looking at service records the car started throwing this code at around 45K. TC and trans are both original. Car drives fine with no slipping. Is going on 6 years like this. I am going to keep driving it this way and just replace both when the trans dies. I too was paranoide that this code meant you had a death sentence, but am now thinking it really is not.

[ttboost]

Death knell? Probably not. But I think it depends on the condition of your car. If it is modded and making fairly decent power, I think the life expectancy is greatly reduced. I got the 17125 code very shortly after I bought my car (68k miles), and I flashed it about as week after I bought it. I then put a TC in it at about 72k, tranny died at 85k. Coincidence....I think not. If you have the code, and you are "stock", or have a "not too aggressive" flash, could very well last a long time. But don't be fooled into thinking it is not a problem.

[lswing]

Death knell? Probably not. But I think it depends on the condition of your car. If it is modded and making fairly decent power, I think the life expectancy is greatly reduced. I got the 17125 code very shortly after I bought my car (68k miles), and I flashed it about as week after I bought it. I then put a TC in it at about 72k, tranny died at 85k. Coincidence....I think not. If you have the code, and you are "stock", or have a "not too aggressive" flash, could very well last a long time. But don't be fooled into thinking it is not a problem.

This is spot on...so much of it depends on tuned power and driving style...

[Bigglezworth]

Death knell? Probably not. But I think it depends on the condition of your car. If it is modded and making fairly decent power, I think the life expectancy is greatly reduced. I got the 17125 code very shortly after I bought my car (68k miles), and I flashed it about as week after I bought it. I then put a TC in it at about 72k, tranny died at 85k. Coincidence....I think not. If you have the code, and you are "stock", or have a "not too aggressive" flash, could very well last a long time. But don't be fooled into thinking it is not a problem.
Sorry Mike, but I can't agree with this. I put over 50K on the tranny over the course of 6 years in my one RS6 after buying it and it threw the 17125 code sporadically throughout that timeframe. Car had street and track time on it and was driven the way it should be (i.e. - never babied). It was a stock tune for those keeping score. That slushbox failed a bit ago and I'm currently in the process of swapping it out.

On the other side of the fence I have a high power turbo Buick that lays down upper triple digits in power and runs low 10's every day of the week and twice on Sunday. It has a small diameter high-stall Art Carr Non-Lock convertor that assists to launch at 4500rpm. I have yet to change it out for a lock-up style of convertor as I don't drag with it any longer and simply don't drive it enough to warrant the $ and time to switch out. As Bob is your Uncle, I am a firm believer that the fact it is a non-lock style of convertor (as were hundreds of thousands of convertors prior to the period when fuel economy became vogue), has no bearing on the longevity of the transmission running behind it. The longevity of the transmission is a result of the power being pushed through it - period. Improved clutches (quantity/quality) along with improved pump units, valving, etc., all go a long way to a transmission performing better under increased load. The ZF slush boxes that were put in the C5 were borderline and the archilies heal of the drivetrain (DRC aside). The power possibilities of the Cosworth built engines were limited so as to not overpower the poor quality tranny's that ran behind them. What we are experiencing as part of tranny failure is just that IMO.

Torque convertors were designed to slip guys. It's called physics (more specifically fluid dynamics). They are designed these days to include a lock-up feature that accuates an internal clutch (similar to what you would see in a manual style of transmission) that overrides the fluid coupling assembly (pump, stator, and turbine) to now provide a mechanical coupling and lock input speed off the engine with the input speed of the tranny. Makes you feel like you hit another gear as our engine RPM's drop 5-10% and of course you get to put that little bit more power from your engine that was being loss in the fluid coupling effort to the asphalt. Used predominently to improve fuel mileage, their ability to lock input/output shaft speeds has been a huge consideration in drag racing. Has been lots of complications in that industry for years with the technology.

Some light reading
http://www.dragzine.com/tech-stories/drivetrain/lockup-converters-101-the-resurgence-in-heads-up-drag-racing/

[ttboost]

Not a problem Tim..my post was based on MY experience, which I found to be consistant with others. It doesn't surprise me that there may be exceptions, you being one. It is VERY possible that a failing Audi TC has NO direct correlation with a failing Audi transmission (which seems to be what you are suggesting). I just happen to think it is more plausible that a very important driveline component failure can potentially cause another component to fail. These cars are smart, and they "learn" and tend to compensate for other shortcomings. Your example was on a stock car, so maybe a 17125 code on a 50k mile car is the limit? Whereas my 70k mile flashed car only lasted 15k miles, not 50k.

[G2]

The other down side is more heat build up when the TQ slips. May not be critical, but if you're sporting 500 lb/ft....

[DHall1]

Som bitch!

When did you update the signature? The EC tune and in the 10s? Hot damn



Not a problem Tim..my post was based on MY experience, which I found to be consistant with others. It doesn't surprise me that there may be exceptions, you being one. It is VERY possible that a failing Audi TC has NO direct correlation with a failing Audi transmission (which seems to be what you are suggesting). I just happen to think it is more plausible that a very important driveline component failure can potentially cause another component to fail. These cars are smart, and they "learn" and tend to compensate for other shortcomings. Your example was on a stock car, so maybe a 17125 code on a 50k mile car is the limit? Whereas my 70k mile flashed car only lasted 15k miles, not 50k.

[ssassc1]

I just purchased mine a few months back and it has 89.5K miles. Looking at service records the car started throwing this code at around 45K. TC and trans are both original. Car drives fine with no slipping. Is going on 6 years like this. I am going to keep driving it this way and just replace both when the trans dies. I too was paranoide that this code meant you had a death sentence, but am now thinking it really is not.

:thumb: If I can get another 5 years out of my Gearbox. Will be VERY happy

Thanks for the relies everyone!!

I feel a bit more relaxed now :bow:

[ttboost]

Som bitch!

When did you update the signature? The EC tune and in the 10s? Hot damn

Went to Atco beginning of November just to see what was up...first few times I had issues...especially tire issues...found some crap DR's and made another quick trip...it was Chevy day, so only got 2 passes...first pass spun a little bit, 2nd pass spun too, but no where near as bad...I'll do better in the Spring...
1453114532

[Bigglezworth]

What the hell were you racing against that only trapped 50mph?? lol

[kday]

I thought the issue with the failure to lock was that it was due to an internal fluid leak which resulted in lower line pressure and therefor higher wear on the clutches.

My car has had the 17125 code for about 3 years. Only in the last 6 months has there been any symptom other than the lack of lockup. Lately it's been a bit balky at tip in sometimes, and I'm getting the sense that the problem has spread to the gearbox proper. I've had a 6 speed kit waiting to go in for 2 years but I've been waiting for it to get bad. Soon, I guess...

[DHall1]

In the past I was under that assumption as well.

It appears as this is not the case.

I looked at a flow diagr of our trans/TC and it showed the fluid path in locked vs unlocked. I don't think it changes line pressure at all.




I thought the issue with the failure to lock was that it was due to an internal fluid leak which resulted in lower line pressure and therefor higher wear on the clutches.

My car has had the 17125 code for about 3 years. Only in the last 6 months has there been any symptom other than the lack of lockup. Lately it's been a bit balky at tip in sometimes, and I'm getting the sense that the problem has spread to the gearbox proper. I've had a 6 speed kit waiting to go in for 2 years but I've been waiting for it to get bad. Soon, I guess...

[papadoc]

Started throwing 17125 intermittently for the past 8 months, but without any noticeable change in performance. My TC and transmission were rebuilt locally by my independent shop only 20K miles before, but with 3 year warranty. Took the car into the local dealer just for convenience sake for oil change service, and the dealer rep tells me I need a new TC, total charge would be $4390. Said thanks but no thanks, back to my shop. Ran all tests, logged data while driving, TC temps fine, no other codes. They even checked the transmission fluid which was clean. I was told that with hard city type of driving, lots of starts and stops, especially in sport mode with tune or manual tip driving, that the TC can get hot and that this might lead to slight slippage with the flex plate, and that this might then throw the code. Transmission has been fine without any hiccups.
Just adding this as a note of caution for those who find their dealers eager to replace TC when all else is fine. Thanks but no thanks!

[ttboost]

Pretty sure, the 17125 code means that your TC isn't locking up all the time. This obviously means that your transmission is slipping more. It could be an older TC that has a leaking seal, or it could be something totally different. It may not fail today, next month or even next year, but rest assured it is making your transmission work harder. If you are stock, probably last a long time. if your tuned, not so much...

[716YETI]

The 17125 code means you should buy an RS6 with a manual transmission. ;)

[papadoc]

The 17125 code means you should buy an RS6 with a manual transmission. ;)
Well if I could get that installed locally, I'd consider that, but I don't know of anyone doing this on the west coast. For now, with 2 years left on the TC and transmission warranty, I'll just keep on course and hope I have the same good fortune as our friend in Cowtown!

[lswing]

Pretty sure, the 17125 code means that your TC isn't locking up all the time. This obviously means that your transmission is slipping more. It could be an older TC that has a leaking seal, or it could be something totally different. It may not fail today, next month or even next year, but rest assured it is making your transmission work harder. If you are stock, probably last a long time. if your tuned, not so much...

100%....

If you have VAG-COM and some time, hook up and log the TC open/close block, glance at the laptop while driving around. Interesting to see when it's fully open (idle), transferring power (accelerating), or locked (cruising)...I think I got that right.

[Dmb408]

Dumb question but is 17125 a background VAG code or does it actually throw a CEL that would pop up and any code reader could read as a (P0XXX or whatever)?

[lswing]

Throws CEL after about 50-75 miles after it is cleared (by the dealer in my case)...

Any code reader will pick it up.

[papadoc]

100%....

If you have VAG-COM and some time, hook up and log the TC open/close block, glance at the laptop while driving around. Interesting to see when it's fully open (idle), transferring power (accelerating), or locked (cruising)...I think I got that right.

I know that is what my shop did in checking it, and I do have a VAG-COM, and will do that with my son on the weekend. There clearly has to be variability in this, as some here have driven with that code for years without an issue, others not so lucky. Since I have this under warranty however, as long as things are fine, I am not about to pay out of pocket to get a new TC. My only point for those relatively new here is that when the code shows up, it may not automatically mean a very expensive repair job, but I have to believe every dealership will see it that way.

[DHall1]

Confused here...

The trans is covered but not the TC?

What TC was used in the reman?

What trans fluid is in the car?

The code means one thing....tc is going out. Cant sugar coat it or say too much stop and go driving.....did they really say that? Geez. We offer a 3 yr warranty but only if you drive the car at hwy speeds 100 percent of the time.


I know that is what my shop did in checking it, and I do have a VAG-COM, and will do that with my son on the weekend. There clearly has to be variability in this, as some here have driven with that code for years without an issue, others not so lucky. Since I have this under warranty however, as long as things are fine, I am not about to pay out of pocket to get a new TC. My only point for those relatively new here is that when the code shows up, it may not automatically mean a very expensive repair job, but I have to believe every dealership will see it that way.

[papadoc]

Dave, the warranty covers both TC and trans. The TC was rebuilt when my transmission bit the dust. I asked them to use the ACE TC, but they offer one year warranty only, and the shop convinced me that their rebuild was robust and had the 3 year warranty to boot. Trans fluid is not BND. Again, since the car otherwise drives fine, and the only issue is that the code pops up after a while, I decided not to push for a replacement at my cost for the TC as long as the warranty is still in effect. The warranty does not dictate driving behavior. If I don't like the code popping up, then maybe, but I consider it insurance for any type of driving, not a restriction.
That said, it still is unclear to me how some drive with this code for years without a problem developing. I agree that it would not appear if all was well, but the vagaries of this remain confusing to me.

[mik15]

i know of an RS6 which has been driven for more than 4 years with the TC error code, not intermittent but permanent, for about(if not more 60k miles), the car is now over 100k miles and the gearbox is still the original one, never been touched, only had an oil change, the car still runs very well, if you don't know how to test it you'd never know there is something wrong with the TC.

I guess even with the TC not locking up, as long as you do the oil change to eliminate the residue formed by the TC's clutch wearing down, the gearbox will be ok. I have been reading and reading about this TC and its only main function is to bring the impeller and turbine together once you're at a constant speed to improve the fuel efficiency. A broken TC will not increase by much the oil temperature, so again we come to the point where if you change the oil often enough the gearbox clutches will not be damaged. And, of course, a stock car with a normal driving will definitely help in the eventuality you have a faulty TC.

Anyway, this TC saga is fascinating :)

[lswing]

Dave, the warranty covers both TC and trans. The TC was rebuilt when my transmission bit the dust. I asked them to use the ACE TC, but they offer one year warranty only, and the shop convinced me that their rebuild was robust and had the 3 year warranty to boot. Trans fluid is not BND. Again, since the car otherwise drives fine, and the only issue is that the code pops up after a while, I decided not to push for a replacement at my cost for the TC as long as the warranty is still in effect. The warranty does not dictate driving behavior. If I don't like the code popping up, then maybe, but I consider it insurance for any type of driving, not a restriction.
That said, it still is unclear to me how some drive with this code for years without a problem developing. I agree that it would not appear if all was well, but the vagaries of this remain confusing to me.

Sounds about right. A lot of it comes down to the amount of slip (lack of lockup) actually occurring. Then add in a tuned car and driving habits and you'll get a 6 month to 4 year time frame of trans destruction.

Last time I checked in, when the TC doesn't lock it's permanently in max power transfer mode (regulating), therefore constantly sending max power to the trans and it's clutches. The trans clutches will always try and lockup on each shift, that is Valve Body dependent. What you don't want is max power transfer from the engine at all times. The TC actually sends more TQ through when in it's regulating stage.

[DHall1]

Switch to BND trans fluid and retest. His friction modifier add pack is better and his high temp add pack is superior.

I have more but only a second to hammer this out while traveling

[GEN XER]

Hello fellas. Its been a while.

[DHall1]

Willy B!!!!!

How the heck are ya

[GEN XER]

Willy B!!!!!

How the heck are ya

I tried to pm you Dave. Your box is full. I'm great. Retired now. Finally back in an Audi. I posted in the RS4 S4 forum. RS4 Line is the title of the thread.