Before you go about changing your cam sensor, here is a guide to testing the sensor. Only figured this out after I had changed mine. The sensor is behind the cam pulley. Follow the wire from the front of the cam cover, over the top, along to the back and you will find the connector in a plastic clamp at the back of the engine.

There are three connections:- 1)Left-5V supply to the sensor. 2)Middle - 5V pulse returning from the sensor. 3)Right-ground or 0V.
I found that putting pins into the back to connect to the wires worked best. You can also use paper clips but some are plastic coated. Make sure you don't short any of these to ground or it could lead to more trouble!!!!

2015-09-26 14.43.42.jpg

With the ignition on, first make sure that you are getting 5V between the left connector and ground. If not, then you could have a different issue.
Lift the offside (drivers side) wheel and support the car on an axle stand - NOT a jack - so you can rotate the wheel by hand.
If you have the cam cover off, you will be able to watch the cam pulley rotate.
Select a high gear, I choose 5th, and while monitoring the voltage on the centre pin, rotate the wheel. This will rotate the cam pulley (obviously) which has a missing portion in the iron ring that passes through the gap in the sensor.

When the iron ring is in the gap, it should show 5V. When the missing portion of the ring is in the sensor gap area, the output should show 0V.

2015-09-26 14.49.06.jpg
2015-09-26 14.50.34.jpg
So, as you rotate the wheel, it should show 5V and then 0V every now and then. If you are not showing a 5V output at any stage, check the connection of your pins to the cable, it could be that. If when rotating the wheel it doesn’t change to 0V

Hope this helps someone.