P0010 Chevrolet -

Question

2009 Chevrolet Malibu lzt 2.4 Ecotech check engine light p0010.
Ok I know it says cam pos but this light comes on every time we fill it with gas.
goes off when the tank it half full, I can reset the code and my code reader says no faults but the light is still on till it gets to half tank, so I don't think it has anything to do with cam pos.
anyone seen this problem before.