Cabin Temperature Sensor
An electronic sensor inside the passenger cabin that monitors interior air temperature to help regulate automatic climate control systems.
The cabin temperature sensor (or in-car temperature sensor) is an electronic component used in vehicles equipped with automatic climate control systems. It is typically mounted behind a small vented opening in the dashboard or near the rearview mirror. The sensor measures the temperature of the air inside the passenger compartment and sends this data to the HVAC control module.
Many cabin temperature sensors are thermistors that work in conjunction with a tiny aspirator fan or cabin vacuum to draw air across the sensor for an accurate reading. Using this data alongside external temperature and solar load sensors, the climate control computer automatically adjusts blower motor speed, vent modes, and temperature blend doors to maintain the driver's desired cabin temperature.
If the sensor fails or the aspirator fan gets clogged with dust and lint, the system cannot accurately measure cabin temperature. This leads to the HVAC blowing constant hot or cold air, failing to maintain the set temperature, or erratic fan speeds. Cleaning the sensor vent or replacing the sensor restores proper climate control operation.