hi guys.my mechanic just did a head job on my 2002 a4 1.8t and also put in a new turbo.car runs great but check engine light is on and spitting out code 0010-intake camshaft actuator/circuit open.i erase the code but when i turn the car on again it comes back.what is triggering it to come on??i tried researching online and found nothing. thanks for any input or help guys.