Avantime automatic transmission issues

Sounds familiar. I had similar automatic transmission issues with my Avantime. Have you checked the voltage? In my case, it turned out to be undervoltage causing the transmission to go haywire. What exactly did you check already?

Undervoltage, you say? Interesting. I focused on the oil level and obvious mechanical issues. Where should I start looking for this undervoltage problem? What kind of voltage should I expect?

Yes, undervoltage. Before you start measuring yourself, you should visit a workshop, because the cause is hard to find. I know this sounds strange but it might solve your problem and save you a lot of headache. I am pretty sure that this is the reason. I ended up having to replace some worn-out transmission oil which set me back 240€.

Thanks, I really appreciate the advice! I took your suggestion and brought it to a workshop. Indeed, the automatic transmission oil was worn out due to undervoltage. I had the oil replaced, and it drives like a dream now!