Fuel tank pressure sensor QA

Hi there, quick q...would a bad fuel tank pressure sensor cause faulty readings on the guage? Looks like a possibility on the diagram.... Another thing as per the diagram, will the sensor also cause you to get a 5v reference fail...I am having trouble locating this problem with my van and it only happens in the hot weather. The fuel guage goes berserk,engine light comes on and the van acts like @#$#$. During cold weather, 9 months of it haha, the van fuel guage works and no engine lite..

Thanks in advance.. I'm thinkin it just may be the tank pressure sensor, not the sending unit as it works great most of the year

thankks

Andy