I have a 99 S80 T6 and just recently the transmission when getting on the highway will not shift to 4th gear. I've tried using it in geartronic mode and manually moving it from 3rd to 4th will not work either. All other gears are fine. Any suggestions on what could be the problem? Thanks.

 

Do you have a transmission service message?

 

can you it shift into 4th at lower speeds?

 

I'm not getting any error messages. I haven't tried shifting into 4th at lower speeds. I've only tried on the highway, the number registers as 4th gear but I can tell it's still in 3rd. No way it would register 3000 rpms at 70 and take off when I barely touch the gas if it were in 4th.