labguy

Driving back to work from lunch today and the transmission got stuck in gear and almost got to redline before I noticed it. I immediately slowed down and then it began shifting properly after that. Any ideas?

Thanks for your replies.

C280 Sport

Are you sure you did not hit the gear lever into shifting mode ? Like knock it and have to use it as a manual shift? Did you try a simple TCU reset ?

labguy

I suppose it is possible I knocked the shift lever with my knee. Tell me how to do a TCU reset in case it happens again.

C280 Sport

https://www.google.com/search?q=w209...TF-8#kpvalbx=1

Try this first. Also, when was the trans fluid/filter changed last? I would start with the easy stuff and go from there.

labguy

I did the Trans Fluid at 40K. I now have 128K.

C280 Sport

Ya you are more then likely due for a tranny fluid change... You basically went 90k miles without a flush. Flush the fluid, change the filter.

labguy

I thought it was one time at 39K. And that is it. - no?

dzmitry

I think for 722.9 you suppose to change transmission fluid (not necessary flush) every 40-45k miles.
Between those two actions (transmission stuck in gear and it went back to normal) did you touched (moved) transmission shifter? If you'd accidentally put it in manual mode it would not out manual mode by itself.

labguy

After thinking through what happened, I now believe that I or my passenger moved the shifter. I think it went back into auto mode when I switched it to Sport mode and then back to Comfort.

It has not given me problems since.

I will do more research regarding how often to change fluid.

Thanks for your help.