I search and found this issue.
"I am not sure but he open the dashboard drawer and pull it out. behind that drawer there was a lot of electrical circuits and component and one of the relay was not working. He told me that if you turn on your AC there is no impact on the RPM of your car its mean that this relay is not working. Turning AC on and off should impact on the RPM of your car but bcz that relay was not working so may car RPM was consent even when i turn on my AC. so when he replaced that relay car RPM started to up and down while i turn on my ac. he also set the RPM to 1200. now i can feel that is vibration less

I didn't know that you weren't going to repair the car yourself.
100 € for a filter seems too expensive.
This automatic transmission is the same one used by other Japanese brands. I would suggest that you visit a Suzuki, Mazda, Nissan, Subaru or Toyota garage and ask them about performing the service. If they agree to do it, it means that they have the parts.
If the filter and oil are indeed the problem, neglecting repair will be even more expensive, as soon as the transmission is damaged from neglect

Ok.Thanks for advice.

I did not know that it is possible to adjust the idle rpm on that engine. What did your friend do to set it?

Normally, the rpm is electronically adjusted and there is nothing to adjust. The rpm is programmed in the ECU and then adjusted via a small electrical device on the throttle body. The screw to adjust the throttle valve position is sealed. If that is changed, the engine won't pass the exhaust gas test most likely. Not to mention that it affects fuel consumption in a negative way, if the idle is risen over factory state.

Er hatte es nicht einstellen lassen. Sondern, das Relais was für der Hubmagnet zuständig ist der die Einsaugsklappe weiter aufdreht war kaputt. Sobald die Verdichtungspumpe der Klimaanlage dreht, schaltet dieser Magnet an

Here is a list of possible filter kits. This is how much they should cost. Unfortunately, the shipping is more expensive than the item. I think, the item is exported from The U.S., because the shipment from Australia is usually even more expensive: https://www.ebay.com/b/Transmission-...662/bn_1489853

Soso, er hats nicht einstellen lassen...

Er schrieb, hinter dem Handschuhfach steht das Relais was Schuld dran war die Drehzahl nicht mit dem Last der Klimaanlage mit zu halten. Das Reste was er schrieb war scheinbar ein Durcheinander. Denn, 1200 Drehungen wäre nicht nur für das Getriebe schädlich. Sondern, der Wagen würde sich schnell selbstständig machen, sobald der Fuss vom Bremsen gezogen wird

Auch. Das zitierte stand aber auch noch da. Kurz: Man muss nicht unbedingt nur das Relais getauscht haben. Dem Text zufolge muss mehr gemacht worden sein.

My instruction manual calls for between 850 and 950 rpm in neutral. I don't know why Daihatsu recommends setting the idle in neutral when other manufacturers call for setting the idle in one of the driving gears. I used to set mine at 450 rpm in drive. But, this was a V-8 engine which could idle that slow. This isn't possible with our 3-cylinder engines. But nevertheless, I would have the idle adjusted at an as slow as possible speed in a driving gear. Otherwise, too high an rpm could damage your transmission and put a strain on the axle joints and provoke early brake and suspension wear