I just tried smacking the dash, in case its a solder joint problem in the dash pcb. No joy.

After a bit of googling I checked the following: The Immobilser LED is flashing. If you wait for a minute, it signals a code. Mine is 1:6 so I believe this is a PATS code.

Also you can access the built in diagnostics by holding the reset button on the left stalk while turning the key from 0 to 2. I got DTC codes D900 and E510.

So I will do some more digging.