The passenger side mirror no longer folds in electronically. What is the likely cause and more importantly, repair solution?

check fuses first! if all are good, then>Manually fold the mirror, and then using the controller try folding it again and then try opening it with the controller. It should sync....If not check the wiring... Have someone control the power fold buttons, while you look closely at the passenger mirror. If you can feel or hear even a faint hum of the motor while commanded, try giving it a little help, but don't force it if you think it doesn't have enough power to extend or retract itself. The motor could be stuck or inoperative. Sometimes when the mirror has been accidentally or manually folded, it needs to be reset by just pressing on the fold buttons a few rounds and let the mirrors fold by itself. if you hear the motor hum whenever the fold buttons are pressed, we can assume that the circuit on that side is ok and that a jammed or stuck mechanism is preventing it to move.