Rider 500 not connecting to cardo freecom 4 plus

As the title says. I can't connect my Tomtom rider 500 with my cardo rider 4 plus. My phone is not a problem but when I try to do it to my headset it tells me I need to use a headset without a pincode. Now I know my pincode so why can't I just put that in. It simply refuses to accept it. Both where very expensive, you really talking me this can't be done? Any help would be appreciated.