The code C1 is a current sensor short or open. Have you looked at test 1,2-0 to see what the current was at the current sensor. I would look to see if the current changes when turning off center. Hopefully this will help decide is you have an open or short. It seems like you have an open. You can look for voltage at the current sensor. It should be approx 1.2v. if so you have a CPU problem. Anything above 2.5v or below.35 check wiring if nothing then a CSD failure.