According to what I remember of the booklet, and my past experience, No Co code means the frig has turned off because it was out of level, out of power, out of propane. With my 1200 it gave ONE chance only to correct the situation. Make sure you are level, make sure batteries are at least 12.5v (not sure which batteries, with mine it was the engine battery) and check propane. Then you can try to restart frig. If you get the No Co code a second time a technician must reset the motherboard. This was done by pulling all the wires, shorting out the board with a paperclip, and reconnecting. In my case, all worked well for another year or so. Then, probably unrelated, I had a coolant leak and had to replace the coils. This worked well for another year, about $1200, and I traded in the MH for my new Allegro with residential frig.
Good Luck.