1. Coolant Temperature Sensor
1. Coolant temperature sensor on the coolant distribution pipe
The sensor is located on the coolant distributor. It measures the coolant temperature and sends the temperature signal to the engine control unit.
Signal usage:
Coolant temperature is also used to calculate injection volume and ignition timing, as well as to control driving performance.
Effects of signal loss:
When a signal is missing, the engine control unit calculates the temperature based on the family of characteristic curves and uses it for other functions.
2. Coolant temperature sensor at the radiator outlet
The coolant temperature sensor is located inside the pipe at the radiator outlet and is used to measure the temperature of the coolant flowing out of the radiator.
Signal usage:
The system controls the radiator fan by comparing the signals from two coolant temperature sensors.
Effects of signal loss:
When the coolant temperature sensor signal is missing, the temperature of the coolant temperature sensor is used as a substitute value.
II. Front/Rear Oxygen Sensors
1. Pre-oxygen sensor
The oxygen sensor before the catalytic converter is a step-type oxygen sensor. This type of sensor is suitable because it can operate with an excess air coefficient of 1 in almost all engine operating modes. The sensor is bolted into the exhaust pipe near the engine, before the catalytic converter. The system uses this sensor to determine the residual oxygen content in the exhaust gas before the catalytic converter.
The oxygen sensor heating device is responsible for rapidly bringing the oxygen sensor to its operating temperature.
Signal usage:
The engine control unit identifies whether the engine is operating with a rich or lean air-fuel mixture based on the signal voltage.
Effects of signal loss:
When the signal fails, the excessive air coefficient is not adjusted. Instead, the injection volume is controlled in advance. At this time, it is forbidden to adjust the excessive air coefficient and the activated carbon canister device enters the emergency operation state.
2. Post-oxygen sensor
The post-oxygen sensor is also a step-type oxygen sensor.
The oxygen sensor heating device is responsible for rapidly bringing the oxygen sensor to its operating temperature.
Signal usage:
The oxygen sensor after the catalytic converter is used to detect the function of the catalytic converter.
Effects of signal loss:
When the signal fails, the catalytic converter function will no longer be monitored.
