Does anyone know about these devices as I can't see anything in the car but I think I'm looking at the wrong thing online please help me

 

Got no idea what you mean....

 

Trevor I'm assuming this is to do with your gearbox fault, the gearbox has an interlock to stop you selecting gears that the ecu deams to be an unsafe change. Ie if your stationary it won't physically allow you to select 5th and 6th as pulling away in these gears would obviously do some damage. It uses the abs system to sense the vehicle speed and it has been reported in the past that some people have been locked out of 5th,6th and reverse and it was traced to a fault in the abs system, ie faulty sensor, exitor ring etc. that's why I suggested you check for any faults in the system first. Now I don't know how the car physically stops you selecting the gear but I do remember when I had the gearbox out of mine, next to the selector cables there was a electrical plug, does this have something to do with it I don't know it might.
I had a little search for gearbox faults for you but couldn't find much only thing I found that sounded similar to you problems was this http://www.focusstoc.com/forums/topi...t-replacement/ as you can see at the bottom it was traced back to a cable that had popped loose, might be worth a quick look