Audi C4 TDI Automatic: Strange Shifting Behavior

Hello fellow enthusiasts,

We recently acquired an Audi 100 C4 (engine type AAT) with an automatic transmission, license plate code CDS.

The following unusual behaviors are observed when shifting gears:

'In the first and second gears, you have to rev the engine to around 2200 RPM just to get the car to accelerate in a somewhat normal way. We're used to different RPMs in our other C4 TDI with a manual transmission... Is it normal for the torque converter to only start working properly at these RPMs?'

'2. When the car is cold, the transmission shifts normally. However, when the car is warm, for example after about 10 km, the shifting from 3rd to 4th gear is delayed. This means that when shifting, the engine speed increases from 2000 to 2300 RPM for about 1 second, resulting in a loss of acceleration, before the transmission abruptly engages 4th gear. This change in shifting behavior roughly coincides with the opening of the coolant thermostat and only occurs when you have been driving in 3rd gear for a longer period. When overtaking (kickdown, briefly accelerating in 3rd gear, then releasing the accelerator -> shifting to 4th), the transmission shifts normally even when the car is warm. What could be the cause of this?'

3. Die Wandlerüberbrückung funktioniert nur im 3. und 4. Gang, nicht jedoch im 2. Gabbreviations
Ist das normal? Kann das Steuergerät für das Getriebe so codiert werden, dass die Wandlerüberbrückung auch im 2. GanDoes g work?

Note: The ATF has just been replaced, and the ATF level is correct at 60-80°C (I've also tried checking the oil level at the minimum and slightly above the maximum marks).

Scratching my head and always grateful for any tips.

Best regards, Frank L.

Hello, what did the fluid in the transmission look like?
As far as I know, the converter lock-up only engages from the 3rd gear onwards.

The drained ATF was red with a noticeable brownish tint, the smell was unremarkable, but it was significantly thinner than the new ATF.

Did you remove the entire oil pan, or just the drain plug?
I'm asking because that makes a difference of about 4 liters.
'Braun' doesn't sound very good.
If you haven't removed the oil pan yet, now is the opportunity; you might find something.
Yes, remnants of the brake linings (are they called that?).
And don't forget to remove and clean the filter.

I left the oil pan attached. In my opinion, the transmission doesn't have brake bands, but rather multi-plate clutch packs?!?

Despite everything, I would suggest taking a closer look at any larger pieces in the oil pan; I think you'll find something there.

Hello,

No debris in the oil pan, just a thin layer of wear. Oil pan cleaned, intake screen replaced, ATF filled---still experiencing the same issues.

The gearbox is likely also designated as 01K, with the last letters being DX.

Does anyone have any HOT tips, a service manual (SM), or a repair guide?

Feel free to send emails with attachments to [email protected].

Still annoyed about the bumpy transmission, but with...

Best regards, Frank L.