Ok,so we have a few options here.The diag equipt may be inadequate for the job.Try disconnecting the battery for 10 mins,this may re-boot the diagnostic system.If this still gives no comms,then we are looking at a possible wiring fault,or one of the access lines to a module is corrupt,as they all share the same diag wire link.Lastly,have you tried it with engine running?

Firstly,under no circumstances bridge or short out any wiring in the obd socket.Serious damage can occur.I would check the wiring behind the obd socket ,to make sure the connections are intact and clean.Pin 7 is the important diag line.My feeling is that one of the electronic modules connected to the diagnostic line is causing the problem.However this takes time and knowledge to work through.If the car has electronic climate control,try disconnecting this first.