Where is the coolant temperature sensor usually installed?

[Alaina]

The coolant temperature sensor is usually installed near the thermostat on the cylinder head at the interface between the engine and the transmission. The function of the coolant temperature sensor is to detect the temperature of the engine coolant and transmit this signal to the engine's electronic control unit (ECU). The ECU adjusts the injection time, ignition timing, and idle speed accordingly based on this signal, which can also serve as a control signal for other systems. The impacts of a faulty coolant temperature sensor include: 1. When the coolant temperature sensor fails, the engine cannot accurately calculate the fuel injection amount, leading to engine shaking or black smoke emission, which affects its power performance and fuel economy; 2. The engine cannot accurately calculate the theoretical idle speed, resulting in unstable engine idle; 3. When the coolant temperature sensor experiences an open or short circuit failure, the cooling fan will operate at high speed.