Cam sensor FR2 td

Good day, I hope someone here can help me, I had an assumed blow head gasket on my 2010 Freeland 2, td. I was referred by a trusted friend, to a mechanic. He seems to have messed my car up. After having it at the Auto Electritions, we came to the conclusion that the cam sensor is not sending a pulse at the correct time. Can someone please send me instructions on how to set it myself, if it is at all possible.

The timing of the cam sensor is completely related to the timing of the cam. If the timing belt timing isn't correct, the cam timing will be incorrect, and the sensor will report this.
Changing the head gasket (not heard of one failing) ob the FL2 is a long process, and needs to be done by someone who is suitably experienced in such this.

The cam timing is pretty easy to do though, but does require the correct timing locking pins, or errors will result.