9000 L4-2290cc 2.3L DOHC Turbo EFI (1992)
Cabin Temperature Sensor / Switch: Description and Operation
In Car Temperature Sensor (Cabin Temperature Sensor)
The sensor has a built-in suction fan which sucks cabin air past an NTC resistor. NTC stands for Negative Thermal Coefficient and means that
resistance decreases as temperature rises.
The cabin temperature is the ACC control module's most important measured value and is compared with the selected cabin temperature to decide
if the blended-air temperature should be raised or lowered.
Cabin temperature is adjusted with reference to the outside temperature to achieve the physical sensation of the selected temperature. If the
difference between the selected temperature and the adjusted cabin temperature increases, the speed of the ventilation fan will also increase.
As heat behind the facia affects the reading from the cabin temperature sensor during short stops, the sensor suction fan continues to suck air
through the sensor for 20-50 seconds after the ignition has been switched off.
If there is no reading from the cabin temperature sensor, temperature is set at +18 °C (64.5 °F).