Elc mirror will not reset to driving position

Most things such as this with position readings are controlled by a memory setting. When activated there is a preset setting sent to the controller, that's why I asked if the other side is fine, or it doesn't have the automatic mirror. Most have settings for both mirrors, and they both move. In most actuators there is a voltage signal sent and then returned to the controller. It the signal is not returned back to the controller as to where it's position actually is, the controller will continue until the feedback returns to say it is at that point, and then it will stop. In most cases the problem is in the actuator, being exposed to the elements, and normally the mirror is the issue. It can be monitored with the proper scanning tool, and diagnosed properly to find which is bad, mirror, wiring, or the controller. Find someone with the proper tools to help you check it.