This is usually an age-related issue caused partially by poor design/assembly of an internal ribbon cable which connects the CF card plug within the memory card slot to the camera. However, the code also indicates either a poor memory card or a poorly seated one, so before looking at more serious causes try giving your CF card a wiggle and also try another CF card to see if there's any improvement.
You have two choices:return the camera to Nikon for repair (usually it's a fixed fee repair and far less than the cost of camera replacement) or you can do it yourself if you're familiar with general simple electronic repair principles such as knowing to wear an anti-static wrist strap. If you make a real hash of the DIY attempt, then Nikon may either charge more than the standard fee or will refuse to attempt a repair and will charge you for the investigative work only and to ship the camera back to you.
There's a Japanese website which shows how to repair the internal hardware problem, the pictures are clear but it's not much use if you cannot read Japanese. If you click
here you'll be taken to the original website, and if you click
here you should be taken to a Google translated version. You may need to view the link using the FireFox browser with the FoxLingo translation add-on (all at no cost).
Note that the ribbon connector in the pictures may be one of two types. One of them unlocks the ribbon by sliding a couple of catches on either side, the other works by flipping a broad section across the top upwards. Once the cable is unlocked you can remove it and then squarely replace it again locking it back into position. Often this action alone will fix the fault. The sixth picture (single red arrow with Japanese text) points to a foam block which is supposed to cushion the cable and isolate it from strain. Sometimes it's too tight and slowly pulls the cable out of it's seating, sometimes it's too loose and allows the cable to flex a bit every time a CF card is removed or replaced and other times it's broken down into a sticky corrosive goo. Note that sometimes you'll find that the ribbon cable has cracked and broken one or more of the electronic tracks. If this is the case then you'll need to order spare parts and will need to disassemble your camera further to fit them. Nikon will usually include this within the fixed fee repair if found to be necessary.