recently bought a 2004 audi a6 2.7t quatro 94k its been driving good dont really use it much have a work van that i drive. Its my first really nice car. I just did its first oil change and the check engine light came on the day before the mechanic pulled the code and it said p0741 Torque Converter Clutch Circuit Performance/Stuck Off i have no idea what that means i need some help asap i want to really take care of this car. Any advice is much appreciated thank you.

 

94k miles is time to have transmission fluid + filter change. To prolong its life, the maker ZF suggests this service at >60k mi.
This service needs Audi specified fluid and procedure (more than 2 hrs), find a garage specialized in Audi VW Porsche. You can google search "Audi + your state or city", then zoom in or out the map and check listing on left. They may come with reviews.
The garage should have the VAG-COM software to best diagnosis your Audi. After the service they can clear the light for you and see if it'll come back to decide next step. Hopefully this can save from big tranny job.

 

thanks man i need good news this really threw me off because the car doesnt feel like its loosing power or anything i will definitly take ur advice and start from there whats vag com again?

 

You should have a mechanic that knows ZF transmissions check the fluid level Don't waste money on the change just fill it!

I would bet your TC has seen better days and you need to replace it.

 

TC replacement -> parts $700-900, labor $900-1300.
Your mechanic provided the OBD2 code, not the VAG one-17125.
I'd assume he has no VAG scanner?

One could drive like this for K miles, replace the filter, ATF and drive.
Note that not all 17125 codes are caused by TC's lockup clutch's seal failure.
Some wiring -electrical connections issues could be fixed (by themselves) while replacing the TC.
Generally speaking - your car is in the mercy of the Audi's gods.

 

Hey whats up? I just got my 2001 A6 2.7 tq running and had some issues w/it, got 'em resolved and figured I'd post and maybe share my success story lol. I noticed a lot of ppl having problems w/ P0741 and P1829 without alot of fixes posted so heres mine.

I bought the car not running, needing a head gasket. My dad and i pulled the motor, pulled the heads, discovered in addition to needing a head gasket 6 intake valves were bent. Long story short, we changed the valves, changed the lifters, both headgaskets, put the motor back together, reinstalled it back in that oh so small space underneath the hood where Audi decided it would in fact cram a rather large twin turbo 90 degree six cylinder and a ridiculously long automatic transmission. Hah, the car runs great! Woo Hoo!
I took it up to a buddies shop in Glens Falls NY and he looked it over good, hooked up a few wires that had gotten missed and I drove it home.
Next day the CEL comes on and it starts going into LIMP MODE!!!!!! AHHHHHHHHH!!!!
So I had 4 codes when I tooki it to to get it inspected:
P1423 Bank 1 Air flow
P1411 Bank 2 Air flow restricted
P0741 Torque converter clutch circuit stuck off
P1829 Pressure control solenoid open short to ground
hmmm....

I really wasn't worried about the first two codes (for air) but the second two scared me alot. I called around to a few places who might know about P0741. Finally I called my parts guy that I've been buying from since '03 and was given another number for and Audi tech. The garage that had pulled the codes had told my that my transmission was possibly done for and I told this to the tech. He said that in the absence of a burnt smell coming from the car my transmission was fine. What was actually causing my car to say P0741 was a bad GEARBOX SPEED SENDER located inside the tranny. It wasn't reading the torque converter rpms correctly apparently and was causing the fault. The even better news was that it is in a (relatively) easy place to change!! So asap I ordered one and installed it. We had to drop the pan and the valve body and it bolted right on. I took it back to my friend in GF and the air codes and P0741 were gone!

All that remained was P1829 for the solenoid. This time I called a guy @ZF of America who was very helpful. He told me which was #4 solenoid on the valve body, and i got one from my parts guy and installed it. Oddly enough the car was still going into limp mode, and throwing the same code. But one thing I forgot to do was reset the TCM after replacing the solenoid. We peeled back the carpet, unplugged it. (I accidently started the car w/ it unpluged) I plugged it back in, started the car and P1829 was gone.

The car now drives great! Can't wait for snow filled parking lots!

 

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"GEARBOX SPEED SENDER"

Do you remember if the INPUT or the OUTPUT sensor it was?
Any part# or Audi part# - N82 ???
What was the price you've paid for the parts?

 

Hey nemohm
I don't know if it is an input or output sender but here is the part number: 01V 927 321 B

I could have gotten it from my local Audi dealer for $75, but opted to pay $65 from a different German parts store. It took about 2 days to arrive. Wasn't very difficult to change at all. If your a do-it-yourselfer you can manage just fine

Cheers
nossis_nave

 

Looks like G182 -Input Speed Sensor.

You are one lucky champ because the DTC related to the sensor are :

17100 - Transmission Input Speed Sensor (G182): Implausible Signal

The shop that diagnosed it is one you should keep friendly connections with.

Also, your part guy is one you should buy beer to.

Thx,