Operation CHARM: Car repair manuals for everyone.

Inside Air Temperature Sensor Description

The following sensors affect the automatic control of the in-vehicle temperature.
^ An in-vehicle sensor
^ An outside air sensor

Both of the sensors are temperature-sensitive thermistors. The resistance of the sensors varies inversely to the temperature. The resistance value determines level of the signal that is sent to the heater-A/C control. The heater-A/C control microprocessor uses this information in order to develop command signals for the following components:
^ The vacuum solenoid module
^ The temperature motor actuator
^ The blower motor pulse width module

A hose duct connects the in-vehicle sensor housing to an aspirator. Air flow from the HVAC module creates a slight vacuum at the aspirator end of the hose.

This vacuum completes the following functions:
^ Draws in-vehicle air over the in-vehicle sensor
^ Improves the accuracy of the cabin temperature that is predicted by the sensor