On my way back from a relative today on the Interstate, I got the "Transmission Service Required" message and immediately thought, oh fun. However nothing else seemed off, it drove perfectly normal. I decided to stop at the rest area and turn off/on the car to see if it was a fluke, maybe from the pouring rain somehow or who knows what. Well on the restart the messages had cleared on their own but when I moved the shifter to D, the dash and indicator both said N. Now I know I have some problem problem. Went back to Park and shut off/back on the car. This time it went right into drive with no issue and off I went the last 20 miles or so home with no problems or messages.

Once I got home I went to park and now the transmission won't leave Drive. Shifter is locked back in park, but it says D. I couldn't take it out of Park again so I shut the car off....but then it wouldn't give me my key because it's still reading D. Conversely it wouldn't even attempt to restart either, probably for the same reason. My only recourse was to disconnect and reconnect the battery which gave me my key back but alas still says D.

I'll have it towed over to Volvo tomorrow but anyone have any ideas what this could be? This is my first manumatic which I know is way more electrical than I'm used to so is there a sensor or circuit controlling the whole thing that's failed? There's no noise, no messages, and it's been driving perfectly fine, so I feel as if there were a real transmission problem I would tell some other way.

 

I'm betting a problem in the sensor for the shift lever position and not an actual internal trans problem based on your description. If you get lucky the sensor might be loose but more likely it's failed internally. Also betting either a dealer or junkyard part.

 

You were close. And I did escape pretty easy. For anyone else that happens to be in the same unique spot, the battery was shot dropping voltage all over. Further, the battery was cracked and actually leaked on to the transmission wire under it cracking the bracket. New battery and wire fix mean a like new car all around. phew.