In many late-model vehicles, the need to manually adjust heat and air conditioning has been eliminated. You can actually set your car’s computer to regulate the cooling and heating process based on the temperature at which you feel most comfortable. In order to do this, the computer gathers information about the temperature both outside and inside your vehicle. The ambient temperature sensor (switch) is what monitors the air temperature. It does it by either decreasing or increasing its resistance according to the fluctuations in temperature, and then delivering the necessary information to the computer, which increases or decreases the temperature according to the preferences you have set.
Any time you are using your heating or air conditioning, the ambient temperature sensor is working. There is no specific life expectancy for an ambient temperature sensor, but like all electronic components, it is vulnerable to damage due to corrosion or short circuits. Additionally, because it is usually located just behind the front grille of your car, it is also easily damaged by impacts. In fact, even a minor collision can cause damage, and if the sensor fails, you will only be able to use your heater and air conditioner in manual mode. This doesn’t affect the safety or drivability of your car, but it will affect your comfort. Signs that your ambient temperature sensor control (switch) needs to be replaced include:
- Climate control system will not work in auto mode
- Climate control system works in auto mode, but does not operate correctly
- Outside temperatures are displayed inaccurately
If you suspect that your ambient temperature sensor control has failed, have it checked by a qualified mechanic. They can diagnose the problem, and replace the ambient sensor control (switch) if necessary.
This article originally appeared on YourMechanic.com as How Long Does an Ambient Temperature Sensor (Switch) Last? and was authored by Valerie Johnston.