Nissan micra 2003 k12 p0340 fault code

my daughters 1L k12 micra has the orange EML light come on if I read the code it comes up as p0340 camshaft position sensor.
I can clear the code with OBD11 scanner ,the car runs OK but the EML light came back on again after a week,can clear code again and car starts and runs OK,any idea,s thanks Tim