I had my cdr23 replaced for right hand knob not working consistently ,it was under CPO so dealer replaced. I've heard the units can be finicky. So far so good with the replacement. I think replacing it with something different would be nice but as mentioned you are looking at head unit etc etc. so I have left mine stock for now.
You can find the manual for it online check
RennTech.org
I am pretty sure you can get codes from it but I haven't done that myself yet.