Jaguar XF stuck in (d) drive & Obd not responding

Hello every one.i bought (XF)from a family friend.first 4 months don't have any problem.but last week car stuck in (p).So I leave the car as it for couple of hours and it starts work ok.but yesterday it stuck in (d)drive.called dealer but its bank holiday so they can't do any thing till Tuesday.so I try local garage they come to check the car.but no luck coz Obd port not responding.now I am confused coz I read every where if (XF)stuck in gear it's 100% gear selector.i arrange the part as well.but have doubt if it's gear selector or some thing else wrong in the car.coz of Obd port.plz help me thanx