Switch inputs: Description

The purpose of this monitor is to detect errors with the state of the PRNDM lever. Since the 'Plus', 'Minus' and 'Button' flags could be raised regardless of where the shift lever is, it is not possible to establish if a fault is present by considering the switches.

This routine considers the PRNDM flags and raises an error flag if a failure is recorded. It also writes a variable, to aid the diagnosis of the fault by counting up how many of the switches are closed.