cosmobeauregard

I am the owner of a 2006 Audi A6 Quattro 4.2L with Tiptronic 6 Speed [sometimes] Automatic Transmission. I am the original owner and like most passionate relationships, we have both loved and hated each other for the past 10+years and 172K miles. Unfortunately as of late she has developed a new strange personality quirk; in Automatic Mode (D), if I am giving the spurs to this pregnant wombat, she will shift through the gears just fine until I get to the 4th to 5th shift. At this point she will attempt to go into fifth but then it will act as if it wishes to shift back down into 4th without ever fully reaching 5th. Under low power settings the 4 to 5 shift goes off without a hitch. Normally, I would suspect a solenoid issue however in Tiptronic mode 4th to 5th works fine no matter how far I wind it out. Also, when in Sport Mode (S) she works every time with no hesitation what so ever without any input from me when to shift.

In addition, if I have her on the Interstate for about an hour or so then exit on to secondary roads it wont be long before I’ll get the dreaded Flashing Red PRNDS indication along with the associated greatly reduced power output until I shut it off. After I re-start this split personality monster, Viola; suddenly we’re best friends all over again.

Vag-com shows a most helpful Fault Code 0000 "Improper Gear Ratio detected" as the only fault code stored. My question to The Sages of this Forum is why is this happening only in Auto Mode (D). The shift Program in Sport Mode (S) will shift perfectly using its programs shift points. It’s almost as if the Auto Program or its controller is at fault. What say ye now? If it will require a Tranny Overhaul then I’m afraid our 10-year relationship will soon be over and I will be herding around a Minivan or whatever else the wife wishes.

Cosmobeauregard

4Driver4

When was the last time the ATF was changed? Is the level correct?

cosmobeauregard

ATF & filter was recently changed (last 4 months or so)

FormulaElement

It's the solenoid that are causing you problems. Consider yourself lucky to get that far without problems. I made it to 105K before needing to do it. They're easy to replace, but be warned your transmission might not shift as smooth as it had before.

Even though these transmission adapt from worn parts and learn from your driving style, the solenoids have a pre-loaded baseline (solenoid values) that they go off of. Unless you purchase a whole new Mechatronics unit that comes with programmed solenoids, the baseline stored in the TCM and what he solenoids can actually do will never match. It won't cause harsh shifting, just at times don't expect buttery smooth shifting.

cosmobeauregard

I had pretty much narrowed it down to either the #5 solenoid or the Torque Converter (probably both). I believe I will change the N371 solenoid along with the #5 solenoid for starters. One thing is certain, if Ii ever get run over by an A6 I will definitely be able to identify it with as much time as I've spent under this puppy lately. Might even be able to fix a couple of things as it rolls over me.
Thank you for your input and please hold me accountable from making the worst sin possible on these forums.
Make sure I post the final outcome. If you come to these forums looking for answers, have the common courtesy to post what cured it for you. It doesn't matter if you think it makes you look stupid.

To quote my Grandfather "I'm barely smart enough to realize just how stupid I am. That still puts me ahead of a lot of folks though"
Thanks again,

cosmobeauregard

Ok as a fulfillment of promise made... I will finish the story on my A6 Transmission problem. Read the above comments for a brief overview.
So, there I was performing the first stage transmission fluid flush using Valvoline High Mileage Mercon fluid from WalMart. I was under the car with it running pumping fluid back in all the while unsuccessfully trying to keep my arms off of the Exhaust Pipes that call this same location home.
Stage 1 flush and filter change finished a quick road test was in order. Results it shifted much smoother but still had the 4th to 5th gear Special Olympics stutter. So, after all of that I decided to change some solenoids. I reviewed every piece of online documentation in preparation of the planned major surgery right down to the solenoid colors depicted in every photo of of a 9L transmission solenoid pack. Jumped on E bay and purchased a set from Miami for $290! Comparatively a smoking deal! The plan was to wait for the 2nd stage Transmission Flush until my solenoids arrived and kill Bird 2 with only one addition visit to the local Hospital Burn Unit.
Solenoids arrived, the colors just as I ordered and I drained the 1st stage fluid and dropped the Transmission Pan. Started removing solenoids and DOH! Obviously my Audi didn't read all of the online content nor did it bother to look at all of the identical pictures I did either. My Transmission had the audacity to have different colored solenoid from the docs I was using as my guide. It had more yellow solenoids than blue ones and I was counting on the dreaded 5th gear Blue solenoid as the culprit. Except now it was yellow! As I didn't have the proper number of Yellows to Blue I was down to Rock Paper Scissors as to which ones to change. Starting with 5th and working down sequence I had to reuse 6th and 1st. This put a serious damper on my mood while I finished both the solenoid and the flush.
Here's the don't ever do this caveat. I relied on data and not what was actually in my car. Very very stupid and completely my fault. However it worked and rather than paying for a $4000 trans replacement. I got away with basically $400 dollars worth of fluid, filter and most of solenoids. I've never been as lucky in the past nor will I ever play the lottery this day forth. All of my allotted luck was used up with this one roll of the dice.
Me and Lady Luck? I'll call us even and won't tempt fate ever again.
172K miles
4.2 V8
with Quattro
and still in the game! (Yay!)

Gerarddm

As a newbie I am surprised you did an ATF replacement, as many commentators advise against replacing/flushing ATF once a tranny goes beyond 100K miles. This is for both Audi and BMW.

Nightlifephantom

OP, I would've went with the G13 VW/Audi tranny fluid.

Gerarddm, lots of C6 owners with tranny issues at high mileage has done the ATF flush and filter change and received quality results.

cosmobeauregard

172,000 miles, First Flush, hoping to correct a 4-5 shift hang up? I'll go low ball "Approved" fluid every time. Especially when confidence was low for a successful conclusion.

Have you priced the G13 Fluid? Wow! Especially considering you've got to fill and drain the Tranny twice.

LarryJa

Bravo!
I changed my fluid (LG6+) & filter @160k miles, twice. The old fluid, filter & pan magnets were filthy!
The trans shifts better & I'm much more confident in the trans.
Someday, I may need to change my solenoids, too, & you gave me the confidence to go ahead & do it!
While, these cars are a challenge to maintain, they are also so rewarding to maintain..
Keep it up!!!