Limp mode since going through puddle

Hi guys, So i went through a sizable puddle and instantly the car went into limp mode. It will reset for a bit but come back. I've plugged it in and am getting the same faults every time which are

P1549
N75 wastegate bypass regularly valve open circuit/short circuit to ground intermittent.

P1524
Fuel pump relay open/short

P1256 coolant temp sender open/short

P1672
Fan 1 control open circuit

P1657
AC input/output short circuit to b+

When I erase them these faults come back after a day or so. I've had the n75 valve replaced (genuine) and the ecu pins checked, cleaned the earth under scuttle panel and had the main loom multimeter checked by a vw tech and they are stumped. I'm hoping someone has had a similar issue that could point me in the right direction. Many thanks
Dan

And the vehicle is a...?

Sorry mk4 golf tdi 130 asz engine