Sensors are usually include sensitive components, conversion device and measuring circuit. Primary role is used to measure the cooling water temperature, intake air temperature and exhaust temperature to correct the control parameters, calculation of the quality of inhaled air cylinder exhaust flow as well as purification. Main function is to transmit the temperature signal is transformed into electrical signals to the ECU. Temperature sensor is a thermal component to output resistance parameters by the different temperatures. Temperature sensors can be divided according to purpose: the coolant temperature sensor, intake air temperature sensor and the exhaust temperature sensor. Simple quality judgments: Sensor plug connection with the multimeter film, after heating the bottom of the sensor, its resistance will change significantly. If little or no resistance resistance change output, should be replaced sensor.