The IAT (intake air temperature) sensor would be located in the air filter box or air intake snorkel depending on what engine you have. The high input signal could be as simple as the IAT sensor is unplugged.
Trouble code P0708 means:Transmission range sensor circuit high input
dtccode.com : Evaporative Emission Control System Pressure Sensor High Input
dtccode.com : Evaporative Emission Control System Pressure Sensor High Input
P1401 is DPFE sensor circuit high, check out this tutorial to replace the sensor on your Ford
Intake Air Temperature (IAT) sensor 1 circuit high input. Check the connection at the IAT sensor.
Trouble code P0118 means: Engine Coolant Temperature Circuit High Input Replace the coolant temp sensor
Fuel level sensor A circuit high input.
P0183 Fuel Temperature Sensor A Circuit High Input
both are considered to be hi impedance inputs. If a sensor requires a high impedance in order to maintain accuracy, we usually connect that sensor to the positive (+) input terminal of the op-amp.
That is behind the catalytic converter.
Trans Fluid Temp Sensor A Circuit High Input
it means knock sensor sensor 1 circuit high input (bank 1 or single sensor)