Automatic Transmission Troubleshooting: 8-Speed Issues

Hello everyone,

I'm having a problem with the automatic transmission on my Touareg 4.2 TDI, which has an 8-speed Aisin automatic gearbox.
The vehicle jerks briefly after shifting gears.
Only when upshifting, and between 1300 and 1800 RPM.
What seems strange to me is that the engine speed at idle does not correspond to the input speed of the transmission.
At a motor speed of 630 RPM, the gearbox input speed is 580 RPM.
Can someone evaluate this?
What measurement values and tests can I perform with VCDS to narrow down the problem?
The transmission has already been flushed.
There are no error codes stored in the control unit.

Best regards,
Raimund

That is the same topic as here https://community.dieselschrauber.org/en/viewtopic.php?t=31873.
Here's some additional information. It's quite possible that the switching processes aren't working correctly. Perhaps you should stick to a single topic?
"hg"

Hello Herbert,

Thank you for your feedback.
Debugging is proving to be extremely difficult.
I thought a new topic focusing on the transmission would be better.
Can you answer the question about the different input speeds at the automatic transmission?

Best regards,
Raimund

Hi there,
Between the crankshaft and the transmission input shaft is the torque converter. This is why there are different speeds, especially when idling.
I don't have any experience with automatic transmissions, but I would like to ask: Does the jolt occur during upshifts in all gears, or only in certain gears? Do you notice any brief changes in engine speed while this is happening?
Somewhere between the accelerator pedal and the wheels, the power flow changes, possibly in the transmission. Figuring that out without experience is like detective work.
hg
Herbert.

Hello Herbert,

The jolt only occurs when shifting gears upwards.
It's most noticeable when the engine and transmission are cold.
When the vehicle is warm, the problem only occurs intermittently.
It only occurs within the partial load range, specifically between 1300 and 1800 RPM.
I believe that in neutral (idle), the transmission input speed should be equal to the engine speed.
But I'm not entirely sure about that.

Best regards, Raimund.

Hi Raimund,
Perhaps the jolting can be recorded during a measurement run.
The measured parameters are engine speed, gearbox input speed, and gearbox output speed. The fewer measurement parameters used, the better the resolution.
Can you provide an overview of the measurement values for the Gasoline Direct Injection (GDI) system that are available in VCDS?
hg
Herbert.

Hello Herbert,

I'm going to do some test runs and make adjustments.

Best regards,
Raimund