Sensor, Temperature, Intake Manifold: Operation

A Negative Temperature Coefficient (NTC) resistor integrated in the fuel temperature sensor alters its electrical resistance in line with the fuel temperature (the resistance drops as the temperature rises). The Powertrain Control Module (PCM) uses this reading to calculate optimum engine performance under all driving conditions. If the fuel temperature is high, fuel rail pressure in the system is reduced. The controller quantity of the pressure regulating valve is reduced and the fuel temperature is reduced.

The NTC resister located within the intake air temperature sensor alters it's resistance in line with the charge air temperature. If the engine is cold, the value equals ambient temperature.