For your OSE:

E134 = Steer servo - analogue steer signal input short circuit

Check the tiller wiring harness, you will most likely find a broken wire or 2, this part has been upgraded 3 times to my knowledge, the current units are a lot better OR if your handy with a soldering iron, heat shrink & have some suitable cable you can repair your current one.
Takes me about 15 minutes to fit a new tiller harness, had plenty of practice as I've got a fleet of OSE I look after.

For your RR B3:

E104 = Output 802 short circuited/disconnected

Make sure the first service switch hidden under the dash on the left is OFF, these can get caught when the arm rest panel is removed / replaced, that 1st switch releases the brake in an emergency, lets the truck drive in limp home mode & will throw code E104 at the same time - I've seen this happen a few times.