Odd, I had that same issue when I put in my cndv-40 discs in my AVIC-9. It turns out it was looking for the touch screen connection. I did that same error on my test bench but once I integrated it in the car, it worked (this is a few years back, my memory is blurry). Try that and see if it resolves your problem. Install it using the proper cables (non RCA if I remember) and it should work with the cndv40.
Bzzliteyr