X5 E70 8hp automatic transmission behaviour

[fiE70]

I have a 2011 X5 40d and got some time to time weird behavior in my 8hp70 automatic transmission. The oils to the transmission has been changed 3000km ago and adaptations were reset on that time. With the earlier oils this behavior was even worse.



When the car is started on cold weather (-0,5 C) the shifting is not optimal but the issues appear while driving speed around of 85km/h. The transmission changes the gear to back and forth from 7 to 8 from time to time. Somehow it feels like that the car thinks that it is not a capable of driving car with so low rpm's with the gear 8 (~1150rpm/min). When the engine gets warmed everything works correctly and smoothly and in exactly same situation the gear keeps on the gear 8.

The heating of transmission in that temperature takes something like a 15km of drive.

Sometimes while driving with cold transmission it feels like it is testing for a gear 8 even while the rpm's show in instrument cluster to the level of driving with 7 (you can feel a minor "push").





Interesting part is that while driving the cruise control the gear keeps on 8 even with the cold temperature of transmission. There's no any particular vibrations appearing while driving in manual mode with gear 8 for a very low rpm's (so it shouln't be the torque converter issue?) when comparing the car's behaviour to high rpm's and gear 6 or 7 at the same speed.



Are there some software updates available for the automatic transmission which could improve this behavior? What could be causing this issue or is it a feature of all of these 8hp transmissions with cold oils?