We had a XC42 where we use a hall effect analog device that was mapped to pin 8 and configured as an analog input. The device was connected to Vref A so uses a supply voltage of +5v and provides 0.5-4.5v thru 180 deg of rotation. We first started to see it only indicating from 2.5-4.5v and then eventually we got fixed values that fluctuated based on if the hall effect magnet was present or not. After some trouble shooting we removed the wire from pin at a connector and were getting a fixed voltage of around 4v at pin 8. With this removed the magnet rotated gave us 0.5-4.5v at the output of the sensor.
A data sheet of the sensor is attached. Model # is RTP180LVNAA
We ended up remapping the input to pin 52 and it all worked fine again.
It almost seems like the pull up resistor in the channel was "turned on"???Honeywell RTP Sensor
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