Volvo S40 Ambient Temperature Sensor (Switch) Replacement at your home or office.

What is the Ambient Temperature Sensor (Switch) all about?

Modern automotive HVAC systems have advanced by leaps and bounds over those used just a few years ago. Today, many high and even mid-range cars offer automatic climate control. This function basically allows you to “set it and forget it,” allowing the car’s computer to control the heating and cooling based on your preferred interior temperature. In order to do this, the computer needs information about not only the temperature inside the car, but also the ambient temperature outside the car.

The ambient temperature sensor (switch) is located either behind the front grille or in the front bumper. Its only job is to monitor air temperature (which it does through increasing/decreasing resistance in response to temperature fluctuations). This information is transmitted to the car’s computer, which then adjusts the climate control to meet your specifications.

If the ambient temperature sensor is damaged or fails, the car’s computer will not be able to automatically control the HVAC system, and the heater and air conditioner will only work in manual mode.