Audi4780

Hi Everyone,

I have searched and read all about the transmission problems that people had on these cars. There are many posts about this issue but almost no one seems to follow up on what they did to fix it.... maybe someone can help!

I have a 2002 Audi A6 2.7t Automatic with Sports Mode and TipTronic, car has 120,000 miles.

The car takes a long time to shift between gears then will eventually go into limp mode and trigger the Incorrect Gear Ratio code. It's strange, you have no slipping while running through the gear, but while it is attempting to shift it seems like it is slipping then a few seconds later will finally shift (then at some point will go into limp mode). I have reset the codes several times and each time it comes back with a different gear for the incorrect Gear Ratio. A few times after reseting the code the car will clunk/jerk really HARD in the shift between 4th and 5th (very loud sound and feels like someone crashed into the car).

So far I have:
1. No water in the TCU module
2. Checked fluid level using Audi's complex fill procedure with temperatures (Fluid level was full)
- Also no shavings in the fluid and no burning smell

What do you guys think could be wrong? I am starting to think its related to the solenoids.


I should also add, I replaced the torque converter at 80k since it failed with the notorious lock up issue.

Thanks,
John

Redneck Truck

There are 4 connectors on the transmission: vehicle speed sensor, transmission vehicle speed sensor, valve body, and range switch. Some people have cited connection problems with those.

Did you replace the fluid and filter when you checked the fluid level? The fluid in mine came out a muddy black, and I believe it was originally clear. Ever try to drink a Frostie at Wendy's through a straw right away? Even though it's full, you can't get it through your straw.

Some have related the muddy, sediment-filled fluid to that, also saying that the computer sees a pressure drop as a result and goes into high pressure mode causing the banging shifts, and then the forward drive drum (I think that's what it was called) shatters.

Somebody verify all this - it was straight from the mouth of one of the salesmen at Freddy's Transmission Repair, whose website has a photo blog of a 5HP transmission overhaul. It's worth a look.

Audi4780

I changed the fluid and filter 6 months ago which made it shift smoother. There was no fillings or anything drastically wrong with the fluid at the time of the change.

When I checked it the other day, the fluid looked clean.... it did not look muddy and is full.

I will check all the electrical connectors.... its just odd that while it is running in each gear everything is fine and there is no slippages.... it just takes forever to shift.

Is there anyway to run the transmission in a full mechanical mode?

I will check the electrical connectors next and report back.

mikhailhr

Hi, I'm having that problem now, is the problem fixed? how did you fix it?

maelove

Do you by chance have VCDS? (Vag-Com) You can use it to go into the transmission control module and seeing exactly what the transmission is reading. If one of the values are off, that will tell you where you need to look. You could also look at your solenoids to see if they're opening/closing when they need to. Also look at your RPM's and speedometer, if they're off, chances are the sensor is bad and it's causing your transmission to slip.

SloopJohnB@mac.com

You might drop the pan and filter and valve body and examine the solenoid/valves and speed sensor channels…if you've spent a long time on the internet and on this forum there is a video and pics of a filthified and failed speed sensor, sludged valves, etc.

Prospeeder

The gear ratio code is specifically seeing a non matching input and output speed. Meaning the transmission was slipping. chances of the speed sensor being an issue is pretty small since these O1L transmissions have such high failures. Im sure most going 100k+ on the same oil doesnt do them any favors for long term life.

caplast1@telus.net

I have a similar problem with my 2001 A6 2.8. It continually shows this code, transmission works fine in manual mode, but in 'D' will slip/feel like its in 3rd or 4th. Any ideas? Fluid level has been checked, I added just a little after fully warmed up. I have also replaced the TCM. When you first put it in 'D', the engine barely changes rpm, but when placed in 1st manually or even pulled straight back to 2nd, theres a noticeable change in rpm.

thanks for any help.

Prospeeder

I believe line pressure is increased slightly in tiptronic mode. Which would explain why its works better in manual mode. In auto mode its adjusting line pressure for the softest shifts it can, and its slipping. The trans is junk.

caplast1@telus.net

Dam I hate when the logic equals bad news. That does make sense though.
I couldn't understand why Drive was not acting the same as in tip, but I didn't realize there is a pressure difference.
I guess theres no point to pulling the pan off ??? I was hoping that maybe the oil level sensor is possibly faulty/dirty and causing the 0730 code, and therefore creating the slippage.

thank you for the help