540 it e39 cam sensor code po340
 

I recently purchased a 2000 540it e39 with the 4.4 liter V8. The check engine light comes on and it throws a PO340 code which I am told is a cam position sensor code. The car runs fine. It has the vanos variable cam timing. Wondering if these sensors are known to fail or if I really have a cam position problem. Any input would be appreciated.

Mark O.