I have an AVIC 5201NEX in my truck I use for towing my RV and can not get the fuel price feature to work. I have purchased all of the available services but have not been able to get it to work. Every time I go into settings and fuel I get a message that says "fuel server not available try again later". Well I have been trying for 3 months now so it must be either something I have not turned on. ( yes I have turned on the fuel price service). Any suggestions?