AC Request on Digital 4 Pin D17

Hello ,
I have my AC request wire connected to Digital 4 input (pin D17), When I turn on the AC my fool pedal signals go out of range. My AC Request is battery voltage +13.8 volts. I was told the voltage is too high for a digital input and the excess voltage was bled off to the +5v bus and messing with my FP range settings. Is this true. What is the solution'. All the other brand ECU I have used where +14 volt tolerant.
Ray.
I have my AC request wire connected to Digital 4 input (pin D17), When I turn on the AC my fool pedal signals go out of range. My AC Request is battery voltage +13.8 volts. I was told the voltage is too high for a digital input and the excess voltage was bled off to the +5v bus and messing with my FP range settings. Is this true. What is the solution'. All the other brand ECU I have used where +14 volt tolerant.
Ray.