Tiptronic issues, please chime in!

[jstarr427]

Hey all,
Long time lurker and fairly recent member, haven't had major issues to post for help about, until now. I tried searching this but haven't found too much specific info related to my issue.

Last year I purchased a 2004 A4 3.0 from a customer of mine at the shop I work at, car came in with check engine light, infamous torque converter code. He didnt want to fix the car, so I picked it up for a grand. Car's got 83k on it, a few scrapes but overall in very good shape. Ended up pulling the engine and trans in my garage, Replaced the torque converter with a stage 1 revmax unit, new trans filter and fluid, new timing belt, water pump, tensioners, serp belts, etc... Put it all back together and it runs great!

Except for the trans that still has some issues. when driving in 3,4, or 5, under 2000 RPM and under load like going up a mild hill, the RPM surges up/down by about 200 RPM. Above 2000 RPM it drives fine and doesn't have this issue. I've checked the fluid level 3 times and it's full. Driven the car around 120+ miles and TCM is not throwing any codes. At times if feels like a misfire, but logging with my Ross-Tech I'm not seeing any misfire, or a change in throttle valve angle to explain this.
-Only happens in 'TC reg' mode, when the trans goes to TC ON, Lockup seems solid and I'm not seeing any slip there whatsoever.
-Monitoring Engine RPM vs transmission input speed, you see this:
Does not seem to happen at all in 1st or 2nd
Called revmax, they don't seem to think it's the torque converter, which I tend to agree with since it's not throwing codes for it. they suspect the issue may lie in the valve body but they weren't 100% on that. I'm leaning in that direction too, but I'd rather not throw another $500 or so at this car if that's not the problem.
Any advice here? Thanks guys!

[csosnowski]

Does it seem like the TC is locking and unlocking just from feel and rpm variance?

I ask because I had a similar customer complaint: while driving at slow cruising speed the TC would attempt to lock and unlock, where the rpm would vary 1-200rpm. Felt like a subtle misfire.

I swapped the valve body and the problem went away. As for the P0741 code, I'm not sure as to if a new valve body would eliminate this issue since it usually points to faulty TC. Since you replaced it, I'd start looking at the valve body.

On the 5HP19 transmissions, the valve body fluid passages interface the case with some rubber tubes about 30mm long. Sometimes these sealing surfaces get disturbed. Its worth the fluid/filter to pull the valve body, extract these tubes and flip them over so that the fresh side is facing the valve body. I had one instance where this was the case.

I've got an allroad at my shop right now that has the 741 code and occasionally wont go into reverse or is slow to engage. Rather than pull the trans and replace the converter, I'm going to try the rubber trick first and see if the code stays away.

[jstarr427]

It does seem like the TC is lock/unlocking, but only in the "TC REG" mode. when it goes to full TC ON there's no rpm variance or issues. Towards the right in the pic I posted the two lines are engine RPM and Trans input RPM. you can see as both are steadily increasing under acceleration, there are several bumps or spikes in one line, which is engine RPM, which leads me to believe something is causing the TC to lock/unlock. It does at times feel EXACTLY like a subtle misfire. Most of the time its noticeable in a RPM variance and change in exhaust note from said RPM variance. That was the code, I didn't remember what it was before but it was throwing a P0741 which is why I put a TC in it in the first place. Can those tubes get disturbed without pulling the valve body? I haven't done that yet. Are they available separately if I need to replace them?

[csosnowski]

Usually they wouldn't get disturbed from R&R a TC. I have found that they do sometimes lose their seal over time. Flipping the tube over seems to help.

Linky.

I am not 100% certain that that part is the correct one since it states its for mechatronic units, that is however exactly what they look like minus dimensions.

[diagnosticator]

What brand/specification ATF are you using in the trans? The TCC has three modes: OPEN, CONTROLLED SLIP and CLOSED.

The graph would be a lot more informative if the TCC control mode was logged at the same time as the engine and trans input shaft RPMs.

[jstarr427]

Usually they wouldn't get disturbed from R&R a TC. I have found that they do sometimes lose their seal over time. Flipping the tube over seems to help.

Linky.

I am not 100% certain that that part is the correct one since it states its for mechatronic units, that is however exactly what they look like minus dimensions.

Interesting, Ive never seen a valve body with tubes like that. Then again my VB experience is pretty much limited to Saturns and MB 722 Tranny Conductor plates lol.
I'll have to do some looking to see if I can find the right ones for the 5HP19. Thanks!

What brand/specification ATF are you using in the trans? The TCC has three modes: OPEN, CONTROLLED SLIP and CLOSED.

The graph would be a lot more informative if the TCC control mode was logged at the same time as the engine and trans input shaft RPMs.

The TCC is in controlled slip when it behaves as seen in the graph. That's the only time I've got issues. When in CLOSED mode there is zero slippage. Fluid in the Trans is approx 6L of Vaico fluid in this kit https://www.ecstuning.com/Audi-C5_A6...sion/ES261797/ and 3L or so of Pentosin ATF1. As stated in OP I am 100% sure it is full.

[aaronamerica]

I just bought a 3.0 with this same issue, it's really annoying lol and i know nothing about Audi 3.0 auto trannys but, hopefully I can get this resolved with out spending a grip

Do the tranny needs to be removed to replace this hose? Hopefully that's not too dumb of a question as I'm used to the manual trannys

[diagnosticator]

Interesting, Ive never seen a valve body with tubes like that. Then again my VB experience is pretty much limited to Saturns and MB 722 Tranny Conductor plates lol.
I'll have to do some looking to see if I can find the right ones for the 5HP19. Thanks!



The TCC is in controlled slip when it behaves as seen in the graph. That's the only time I've got issues. When in CLOSED mode there is zero slippage. Fluid in the Trans is approx 6L of Vaico fluid in this kit https://www.ecstuning.com/Audi-C5_A6...sion/ES261797/ and 3L or so of Pentosin ATF1. As stated in OP I am 100% sure it is full.

The Vaico ATF in ECS's kit, is not the correct specification ATF for the ZF 5HP19FLA transmission. The description on the bottle says "Suitable where an ATF Dextron III G/H is stipulated."

The static and dynamic friction properties of the LT 71141 spec ATF and the Dextron III ATF are not the same. The ZF 5HP19FLA trans is designed and programmed with the specific chemical and physical properties of the LT 71141 ATF and ZF Approved Equivalent ATFs.

Pentosin ATF-1 is a 100 Percent synthetic ATF that is specification equivalent to the Mobile LT 71141 ATF specification required by ZF. ATF-1 is on the ZF Approved fluids Listing.

I don't understand why owners are frequently compelled to use unapproved ATF in the tip trans. It seems kinda like a Grown-ups chemistry set experimenting with unapproved ATFs.

[csosnowski]

The Vaico ATF in ECS's kit, is not the correct specification ATF for the ZF 5HP19FLA transmission. The description on the bottle says "Suitable where an ATF Dextron III G/H is stipulated."

The static and dynamic friction properties of the LT 71141 spec ATF and the Dextron III ATF are not the same. The ZF 5HP19FLA trans is designed and programmed with the specific chemical and physical properties of the LT 71141 ATF and ZF Approved Equivalent ATFs.

Pentosin ATF-1 is a 100 Percent synthetic ATF that is specification equivalent to the Mobile LT 71141 ATF specification required by ZF. ATF-1 is on the ZF Approved fluids Listing.

I don't understand why owners are frequently compelled to use unapproved ATF in the tip trans. It seems kinda like a Grown-ups chemistry set experimenting with unapproved ATFs.

It's very simple, cost and availability. Even with the choice of going to the localdealer for fluid, I will order fluid or coolant from university audi in seattle since Kendall auto bought the dealer here. We get a better discount from university as well.

I'm sure that most people don't want to order fluid or go into the dealer where they automatically feel ripped off, hence the use of what is available. I agree that a correct fluid should be used, especially when troubleshooting a fault condition.

We have used the same fluid our transmission shop uses which is a fully synthetic Valvoline MaxLife. It is the bulk trans oil they use on almost everything except the CVT's they work on. We have had good success with it, its more available, and less costly.

I found a post on BITG discussing this: Click