Have you checked the DTC's - a P0600 code is probably a CAN BUS failure. It might be an intermittent connection - I had a CAN BUS wire open at a splice. My initial fix wasn't very robust, and when I was driving the car, all of a sudden, the IC would go crazy, and many of the warning lights would come on. After a couple of seconds it would go away, only to come back a few minutes later. I re-did the fix (soldered everything), and I haven't had that problem ever since.
Good Luck
-Jerry