What are the symptoms of a faulty car evaporator sensor?

[ColinRose]

When the evaporator temperature sensor is damaged or fails, it prevents the refrigeration system from maintaining proper temperature control. Introduction to car evaporator sensors: 1. Working principle of the evaporator temperature sensor: After turning on the air conditioning, the evaporator continuously cools. When the temperature reaches the set value, it sends a signal to stop the compressor. If it continuously sends signals to the compressor, the compressor will keep running. When the temperature meets the set requirement, it disconnects the compressor circuit to stop operation, and reconnects when the temperature rises above a certain threshold. 2. Function of the evaporator sensor: It protects the air conditioning system by preventing frost formation on the evaporator surface, which would reduce heat exchange efficiency. Typically, when the evaporator surface temperature reaches approximately 2-4°C (considered frost-forming temperature), it provides feedback to the AC switch to control its operation. While high/low pressure switch signals are sent to the vehicle ECU to control compressor operation, both mechanisms serve to protect the car's air conditioning system.