Code P0016, where is the camshaft sensor located?

Hello, we do not have proper service information on this vehicle here in the US, but this is some aftermarket info I was able to come up with for a 2012 SEAT Alhambra 1.4L petrol engine. You will have to remove the black engine cover to locate the sensor, since the camshafts are both under the valve cover (cylinder head cover). The camshaft position sensors are usually located at either end of the valve cover since the trigger wheel for the sensor is at one or the other end of the camshaft itself. This is really the best we can do for this vehicle. The crankshaft position sensor (2nd diagram) they are labelling as Engine Speed Sensor, so this Hall Sender (1st diagram) being a 3-wire sensor is most likely going to be a 3 wire Hall Effect sensor which are used for camshaft position sensors, it also looks like the crankshaft position sensor is also a Hall effect sensor. The 3-wire sensor will have a voltage feed wire of usually 12v or 5volts. a Signal wire, and a Ground wire.
So, you will need to locate the cam sensor by the 3 wire colors in the 1st diagram. I've listed the colors on each diagram. The two colors per wire will be green wire with a red stripe for example. Hopefully you will be able to find the sensor ok.
This code can occur if the crank and cam position sensors are out of sync, but since you can still start the engine and it runs ok, this is most likely just a bad cam position sensor or a wiring issue to the sensor.

Here some guides to help you if needed, sorry we couldn't be more help:

https://www.2carpros.com/articles/camshaft-angle-sensor-replacement

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement