I ran into this issue after buying my used 2001 Outback Limited Edition wagon. I noticed that sporatically the drivers side mirror partially worked via the electronic movement controls on the drivers side door. All the while the passengers side mirror fully worked without question. To be more precise, the mirror has stopped moving Up/Down, yet will still move Left/Right just fine. Periodically it seems to work with the electronic controls letting me move the mirror up and down. But recently it has stopped again.
I'm pretty sure it's a loose wire, or something solely electronic right in that mirror or a wire leading into it. How would I go about fixing this? Personally it's not a great big issue because my mirrors are set to where I like them, but sometimes at night getting a jerk run up behind me, tailgate me with high beams makes me lower the angle of the mirrors.
Brad