The intake-air temperature sensor determines the temperature in the suction pipe and forwards the voltage signals arising from the temperature to the control unit. This evaluates the signals and influences the mixture formation and the firing angle.
The resistance of the temperature sensor changes depending on the intake-air temperature. As the temperature increases, the resistance is reduced, which reduces the voltage at the sensor. The control unit evaluates these voltage values, since they are directly related to the intake-air temperature (low temperatures result in high voltage values at the sensor, and high temperatures result in low voltage values).