What are the chances?

[na1mt]

Transfer shifted kinda really hard this morning when I put it into gear and all the shift indicators lit up. Pull out the vag and get the following code/fault :

17090 Trans. Range Sensor (F125)
P0706-003 Implausible Signal

Cleared code and lights went back to normal, and it drove fine after, but the code is back. Searched and found similar problem threads, but none that were ever followed up on after. So I guess the question is bad trans or likely smaller issue? This current trans was an Audi replacement right before I bought car approximately 5 years and 10k miles ago.

[speedtrapped]

Wow, at least u have the 300lb paperweight waiting to be installed, for just such a situation.

[na1mt]

Lol....hopefully that's not the problem.

[lswing]

Dunno, but when my trans clutches blew there were no codes, step on the gas and it would slip and slam around gears. Now, when we toasted my tcu a few years back, everything lit up on the dash, makes me wonder of this is electrical. And go have your trans fluid checked, takes 20 mins with a lift.

[na1mt]

Yeah, what I did fail to disclose is that I never reinstalled the weatherstripping on my windshield cowl after I repaired my wire harness going into the main fuse block that failed due to standing water. I took the car through a car wash last time I drove it, so maybe the water got down in the footwell. I guess Ill pull that all apart next weekend to check to see if I have corrosion on the TCU....fingers crossed.

[mik15]

is the F125 switch, have it replaced and you should be just fine, it's not quite a difficult DIY and neither is expensive, i think the switch is cca. $200, this is why the PRNDS lights up, because it doesn't know anymore what gear has been selected due to the bad switch...i had the same problem with my VW Phaeton, managed to fix the switch, but it's a different one than the RS6 has being located inside the car under the lever...

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[hahnmgh63]

I would agree to check for moisture at the TCU, if it is dry then it could very well be the F125 switch but then again I would check the plug connection before swapping out the switch. The switch and plug is easy to access from underneath but a bitch to pull due to the subframe & exhaust. It can be done but isn't easy. What is the latest on the RNS-E? Did you get the Nav disc?

[JSRS6]

Ron, after reading miks post and recalling our talk yesterday, I'm inclined to lean more toward that switch.

[na1mt]

I would agree to check for moisture at the TCU, if it is dry then it could very well be the F125 switch but then again I would check the plug connection before swapping out the switch. The switch and plug is easy to access from underneath but a bitch to pull due to the subframe & exhaust. It can be done but isn't easy. What is the latest on the RNS-E? Did you get the Nav disc?

Mark, thanks...... the disc arrived the other day,sorry I forgot to email you to confirm. The nav seems to be doing everything as it should. Yesterday was the first day I was able to drive car, and the trans issue was there when I got in. I didn't get to actually use the guidance yet, but the map displays properly and I entered in my "home" location. Haven't tried to play around with the antenna yet, I'll just wait until I do the BT module.

[na1mt]

Thanks Mik, looks easy enough to do....hopefully that's the issue.

[TozoM8]

Water gets into the switch. Drill a small hole on the bottom of the switch and spray a lot of WD40 in it to drive the water out. The other thing that can cause this if you park on an incline a lot and have to force the shifter out of park a lot. The cable stretches and it is holding your switch (and manual valve in the trans) between D and N. 2 M8 bolts (13mm socket) holds the cable to the trans. Loosen them and move the bracket froward 1/16".

[SteveKen]

is the F125 switch, have it replaced and you should be just fine, it's not quite a difficult DIY and neither is expensive, i think the switch is cca. $200, this is why the PRNDS lights up, because it doesn't know anymore what gear has been selected due to the bad switch...i had the same problem with my VW Phaeton, managed to fix the switch, but it's a different one than the RS6 has being located inside the car under the lever...

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I've got 1 or two of these switches if you need to replace it.

[na1mt]

I just drove it to the store and back without any issues. I checked for codes when I got back and there were none. Next weekend Ill just pull the passenger footwell apart to double check for water and if that is all good...and install my BT module, then I'll probably just replace that switch just to be certain. Thanks everyone, and Steve Shoot me a pm with pricing and Paypal address.

[na1mt]

.......Tozo is there any particular spot to drill this or not really? Also, is there any way to actually check with a multimeter to see if it is actually in need of replacement?

[TozoM8]

The inside part is plastic (the side towards the trans). I would drill a small hole to fit the WD40 tube and spray some in there. Make sure you don't let the drill go in too far and damage the inside switches. When you are done cover the hole with a dab of sealant.