2013 C- Max here
I had two issues recently... radio froze up and would not work.. then a month later Sirius update froze.
For the first issue fuse #79 did the trick...
For the Sirius issue, #79 did not work. Had to disconnect the low voltage battery. In the original post and picture, the bolt he is referring to is not in the frame of the enlarged pic. It is 5-6 " to the left. There is a thick bloack wirw. Just unscrew that (10MM) and use an extra long ratchet extender and simply disconnect the wire. There will be a few sparks along the way but harmless. I didn't even have to fully unscrew it as as soon as the power went out, I just waited and then tightened back up.
