PrimeAzorean

Hello All,
I have two 2002 Audi A6’s... One is the Avant and the other is the sedan... They are both the 3.0L Quattro. Mine is the Avant and the sedan is my daughters... I’ve been working on cars ever since I was 15 years old and am much older now... I’ve done the majority of the work on all my vehicles including these two, but am a bit stumped with this particular issue...
My daughters A6 has 188k miles on it and runs amazingly well if not for this problem... Several months ago she took it for a drive and this is what is happening:
The car will shift into drive normally, will drive through 1st gear, shift normally into 2nd gear, will shift into 3rd gear for approximately 2~3 seconds and drop into neutral (engine will rev/surge due to the no load condition) and will then lurch into gear... the same thing will usually happen when it shifts from 3rd to 4th gear... It doesn’t feel like it’s slipping in the gear, but dropping out of it entirely.... Once in the appropriate gear it stays just fine... Acceleration if fine, will kick down appropriately, will down shift perfectly... Only happens going into 3rd and 4th... Also, this was not a gradual thing, went from driving fine to this in an instant.

What I have done: BTW the tranny is the 01V-300-050K
1) I have a vagcom code reader and it does not throw any transmission codes.
2) I have changed the transmission fluid and filter with appropriate fluid and filter: Old fluid looked dark, but very minimal sludge on pan or magnets (look better than I expected). This procedure produced no change what so ever... Still same condition with shifting.
3) I have not reset the TCM ... Should I???
4) I have not reset the ECM either... Should I???
Any help or advice would be gratefully appreciated, as the car runs extremely well otherwise and my daughter loves the car and needs it to get to school and back... She has been driving it this way for months now and does not appear to get worse or better, but a nuisance when getting it to shift.
I’m hoping for a ridiculous Audi sensor gremlin or tweak... Please HELP... Thanks.

jcman

Well, when you said you have vagcom "code" reader can you elaborate on what you really have? Is it the real vagcom/VCDS??

When you did the trans fluid/filter service did you do it? or have it done by a somebody else?? The flush method will always cause near death and the fill procedure is very critical for the proper fluid level.

Need more meat on the bones here.

PrimeAzorean

Hi, Thanks for the reply...

The reader is a Autel VAG reader and, I have the free VCDS at the moment... Neither are coming up with any tranny codes... I realize I should upgrade the VCDS and plan to.
I did the fluid change myself and did it to the letter... Used the VCDS to monitor fluid temp during fill up and every thing went as planed (new filter and Pentosin ATF1). I'm confident that it was done properly and it made no difference what so ever.

I fear that it is probably internal to the tranny (ZF 5HP-19) and beyond my immediate level of time and equipment to fix. I was hoping someone out there might have had a similar experience with the symptoms I'm having and had success with superficial remedies like a sensor, vacuum, or reboot of control units. Automatic Transmisions aren't my strong suit, and looking to the masses of experts, that are, for help. Mostly, why it's only effecting 3&4 gear, I would have thought 1st or 2nd would have been more susceptible to load wear... And why the false neutral drop out before going back into gear.

Any more info I can provide? Any suggestions? Thanks!

jcman

Yep that's a tough one to diagnose with the drop-out or shift lag into the top gears and VCDS don't show hydraulic pressure points although it should show something , sounds like one of the shift solenoids are hanging up intermittently, TC unlocking or the TCM is acting up.

At least it sounds like the drum plates are good once the pattern is in sync, VCDS is a lot cheaper then a rebuilt trans.

jorg0370

Since you said you wrench your cars...

If that were my car, I'd pull the valve body, disassemble, clean, assemble, and replace it. The great thing about pulling the valve body is it can be done without removing the transmission from the car. I'm in the middle of disassembling and cleaning mine this week. If you need the car's downtime to be minimal, you might score a used one from a local yard to rebuild, but be careful to get the same model valve body. ZF has a good free PDF spare parts catalog on their website for the 5HP19FLA. Here's a link:

http://www.zf.com/media/media/docume...4/5HP19FLA.pdf

Youtube has a few excellent teardown from an Austrailian. Here's a link to just one in a series: