Pretty sure sensors at the rear end of the camshafts.
Parts
#3 and #8 sense parts
#13 and #15 spinning around.
But you said the codes were for actuators, which sound more like a Vanos problem.
I'm assuming from the "P" codes that you're using a generic OBD scan tool.
You may want to get set up with a GT1 knockoff so you can run DIS and get some better diagnostics.