Kone machines can be so fickle sometimes. The lights on the cpu for 61:U, 61:N and 30 will actually go low when it has seen the magnet. I.E. when the door zone magnet is sensed the 30 light will go low on the cpu. It's counter-intuitive.

The sensors are the cigar shaped sensors right? Not the horseshoe oscillator?

If the 30 light on the cpu DOESEN'T go low when it is within door zone the signal is probably not reaching the cpu. If you suspect the sensor is good, you can trace signal to XB21 on the CCBN (car top board), and then to the cpu from there.
Drawing #E07

If the 30 light on the cpu DOES go low in the door zone then, well, faulting 0071 is a mystery. Maybe something went wrong during learn run or the sensor moved. Run it to the opposite terminal and see if it does it there too.