There is an important part in the A/C system named ambient temperature sensor or ambient temperature switch. When you enjoy the trip in the cold winter or hot summer, you should thanks to the high performance A/C system in your car. There are amounts of parts and sensors in the system working together to make sure you feel comfortable. The ambient temperature sensor, as one of the sensors, is used to measure the exterior car temperature. It is important, especially in some extreme weathers, to know this information so that the car needs significantly more effort to balance the temperature in the car. Here are some signs showing that the ambient temperature sensor in your car is failing: if the A/C auto mode doesn't work; if there is an inconsistent cooling; if there is incorrect reading on temperature gauge, you need to stop driving immediately and check it if the replacement is necessary. Once you decide to change, we are glad to offer you all BMW genuine OEM ambient temperature sensor with a discounted price.