SOLVED: Tiptronic Transmission Grinding Rattling in higher gears

[roadsession]

I was getting this exact symptom:

Grinding / rattling noise accelerating from stand still or in 3rd gear at lower speeds.

I thought my transmission was toast - all the other posts on here talked about needing to replace the transmission.

I read the TSB on here about needing a new TCU which costs $1700.

So I took the chance and reset TCU adaptation values and transmission is perfect now.

Shifts are quicker

Car is more responsive

I reckon the TCU learned 'bad things' when i was goosing the car during the break-in period of the new engine...

[wvicary]

How did you reset the adaption values? I have never heard of a reset fixing a grinding noise.

[wyovino]

Good to hear. Hopefully clear sailing from now on.

[roadsession]

I have never heard of a reset fixing a grinding noise.

me neither.

but read the TSB 3701

The reason for this is the adaptation of the torque converter lockup clutch in the Tiptronic control unit. If the car is driven in a restrained manner or is frequently driven in stop-and-go traffic, the Tiptronic control module adapts itself to unfavourable values that cause the grinding/rattling noises.

The "fix" is to install a new Tiptronic control unit with modified software. The newer control module has the part number 996.618.180.04 (or greater). The latest part number 996.618.180.07 or newer. This TCU ensures that it never learns this 'bad behaviour'. The other cheaper route is to reflash TCU and drive more aggressively...

how did you reset the adaptation values?

Dealer used a PIWIS. Because I did the diagnosis - tech did the reset for free, and bought me an ice tea too :)

Edited March 10, 2011 by roadsession

[1schoir]

I have never heard of a reset fixing a grinding noise.

me neither.

but read the TSB 3701

The reason for this is the adaptation of the torque converter lockup clutch in the Tiptronic control unit. If the car is driven in a restrained manner or is frequently driven in stop-and-go traffic, the Tiptronic control module adapts itself to unfavourable values that cause the grinding/rattling noises.

The "fix" is to install a new Tiptronic control unit with modified software. The newer control module has the part number 996.618.180.04 (or greater). The latest part number 996.618.180.07 or newer. This TCU ensures that it never learns this 'bad behaviour'. The other cheaper route is to reflash TCU and drive more aggressively...

how did you reset the adaptation values?

Dealer used a PIWIS. Because I did the diagnosis - tech did the reset for free, and bought me an ice tea too :)

Regards, Maurice.

Edited March 11, 2011 by 1schoir

[wvicary]

Good result then. I didn't even know the adaption values were resetable on that transmission. Glad it worked out and drive the clappers off it so it doesn't learn anymore bad habits.

[hasteyrb]

Good job!

[roadsession]

Hi everyone - I've received about 4 different messages about this issue on both RN and RT - so I thought I'd give a little more detail.

Some of you have written to say that you went to your local tech / indy and he reset it with PIWIS to no avail.

I'll give you the procedure that worked for me:

1. I went to my local P car dealer - to make sure they had the latest/best equipment.
   
2. I asked him to reset the adaptation values for everything on the car - including TCU
   
3. I then took the car on a spirited drive having it go through ALL shift points
   
4. I idled the car for 10 mins afterwards for the computer to learn the new 'style'.
   

It has been over a year since I got this done and (knock on wood) it is still doing well.

NOW - some caveats - I have a Mk2 C4 - which uses the Mercedes AMG sourced 722.6 transmission that came 2002+.

Earlier models used the ZF transmission so I have no idea whether this will work for the ZF transmissions.