What is the principle of the coolant temperature sensor?

[VonLondon]

The principle of the coolant temperature sensor is as follows: 1. The coolant temperature sensor is a negative temperature coefficient (NTC) thermistor, with a semiconductor thermistor inside. As the temperature increases, the resistance value decreases. 2. The DME calculates the resistance by measuring its voltage value, thereby determining the coolant temperature. The coolant temperature sensor has two pins: PIN1 is the signal line, and PIN2 is the ground line. The higher the coolant temperature, the lower the resistance; the lower the coolant temperature, the higher the resistance. 3. When the coolant temperature sensor fails, there will be a fault memory, and the engine cannot accurately calculate the fuel injection amount. The engine may shake or emit black smoke, and the engine's power and fuel economy will be affected.