Panasonic CN-HW880D

So I&got a 2009 Subaru Impreza that came with the Panasonic Strada navigation system . the other day I had to remove the battery from the car and since putting it back in the radio would not work. This had happened on two occasions before and all I had done to get it going again was remove and replace the battery terminals while the key was on and it started to work again. I&tried that over and over now but it still won&work. Has this happened to anyone with a radio of this kind before, and can anyone help me to get it working again? Thanks!