I have 2 Bimmers, an E46 (2002) 320ci and an E39 (2003) 530i M-Sport. BOTH of them have now had a failure of their PDC system. I have checked them both with the cars in reverse, engine off and key on. All of the sensors on both cars click when in this mode. Do I assume it is the control unit then? If so, do you have any guess as to how much this may cost me? Is there any way for me to just reset them? Where is the PDC module located in the 320Ci? Any help would be appreciated..