i've had this happened to me before.
#1. did you install a new steering wheel with buttons?
(if so, you probably didnt have buttons on your old steering wheel correct)
if this is the case, you will need to make a harness connecting the wires coming from your new steering wheel to the LKM/LCM. There's a DIY somewhere on the internet. This happened to me about 2-3 years ago when i attempted to retrofit a steering wheel with buttons onto my E46. I was having trouble just like you until i found out myself that a wire harness must be created.