Standing in front of your Jeep, look down at the bottom of the front grill. Between the radiator and the bars of the grill, you should see two temperature sensors. These sensors are located at the bottom corners, one on each side. The one on the passenger side is connected to the computer. The one on the drivers side is connected mirror. These sensors are black plastic pieces with a tip on them smaller than a pencil eraser. The connector should not have come loose. TGHere could also be a loose wire somewhere else in the wiring harness. This is covered under your warranty.
I had the OC error when I installed the mirror, but did not install the temerature sensor that was included in the kit. I had to find one that already had the mirror to find out I needed the other sensor.