Gen 2 won’t go into drive park reverse

Hi all,
I have a 2008 208000 miles. It has been running ok burning a bit of oil.
Yesterday I Tried to use it,
It turns on the lights on the dash around the gears just flash green squares.
It will not go into drive, engine won’t start.
My son managed to get a code. P3102.
The boot was checked for water, there was plenty in the wheel well and around the battery base.
Fuses have been checked ok.
It now will not connect to a code reader.
Help please, love the car don’t want to scrap it, but I think to get professional repaired in London would just be too expensive.

 

Thanks for the reply, it turned out to be a large connection plug under the dashboard was only part plugged in. To the left of the radio.
Must be the mileage and the terrible roads at the moment in the uk knocked it loose.