This is a good capture from a 2005 k12.
I'm not sure I understand the ecu looking at the switch on/off? I believe there has to be a tolerance or a window that within which the ecu will not log a fault, so if its slightly ahead or behind where it should be this will not cause a problem.
To me this sounds like a ckp failure and by swapping over the sensors the car wouldnt stall if the fault occurred but would leave you a p0340 code.