I'm working on a Kone KCM831, 2 landing. The elevator is on the top landing, doors open, with no blockage on the light ray. The CPU is a 375 LCECPU40. It is currently showing a F 0015 fault. I do not have a fault book on Site and the one I do have doesn't show that error. Can anyone send me a more complete error book? In the meantime can anyone shed some light on this error? Thanks