what scan gauge monitores oil temp and coolant temp

• 2023-04-04

1. Coolant temperature sensor

It is installed in the water jacket or coolant pipe of the engine block and is in contact with the coolant to detect the temperature of the engine coolant. After receiving the temperature signal, the ECU corrects the injection time and ignition time. The elongated head of the engine coolant temperature sensor is in contact with the coolant, and a negative temperature coefficient thermistor is installed inside it. As shown in the following figure, when the engine coolant temperature gradually increases, the resistance value of the thermistor will gradually decrease, and on the contrary, it will increase. As a result, when the engine coolant temperature changes, the output voltage of the sensor will also change accordingly. After receiving the signal from the coolant temperature sensor, the ECU corrects the fuel injection time and ignition time of the engine.

2. Intake air temperature sensor

It mainly detects the temperature of the air entering the intake gas pipeline and inputs the intake air temperature signal to the EUC as a fuel injection and ignition timing correction signal. It is mainly installed on the intake hose of the air filter and on the air flow sensor.

3. Transmission oil temperature sensor

The higher the temperature, the lower the resistance. The computer measures the temperature of the hydraulic oil in the automatic transmission based on the change in its resistance, which is used as the basis for computer gear shift control, oil pressure control, and lock up clutch control. A semiconductor thermistor with a negative temperature resistance coefficient is installed on the valve plate inside the automatic transmission oil pan. EGR exhaust gas cycle monitoring temperature sensor. The EGR monitoring temperature sensor detects the temperature of the recirculated exhaust gas in the EGR system, ensuring that the system operates normally, and reducing the content of NOx, S compounds, and other harmful gases in vehicle exhaust. The outside temperature sensor, also known as the ambient temperature sensor, is a sensing element of the automatic air conditioning control system. The exterior ambient temperature sensor is generally installed on the front bumper mounting bracket and is also a thermistor. Its function is to detect the ambient temperature outside the vehicle, and the control system will determine the control method based on the difference between the outside temperature and the inside temperature. For example, when the ambient temperature is below 5 ℃, the air-conditioning control system will disconnect the power supply to the compressor clutch, causing the air-conditioning refrigeration system to stop working.