What is the function of the exhaust gas temperature sensor?
3 Answers
The function of the exhaust gas temperature sensor is to detect the temperature of the intake air, providing a basis for the vehicle's ECU to calculate air density. Definition of exhaust gas temperature: Exhaust gas temperature refers to the temperature of the gas after it passes through the combustion chamber in the engine, exits through the high-speed rotating turbine, and remains at the cross-section of the engine turbine outlet. Principle of the exhaust gas temperature sensor: When the exhaust temperature of the engine changes, the sensor automatically generates an induced electromotive force signal. This signal is then sent to the engine integrated regulator to alert the driver of engine overheating. Additionally, the signal is transmitted to the parameter display and directly to the flight parameter collector, ultimately being uploaded to the electronic system monitoring processor. This provides test personnel with relevant data on the engine's exhaust temperature.
I remember the mechanic mentioning during the last repair that this thing is like a thermometer for the exhaust pipe! It's installed near the tailpipe or the particulate filter, specifically monitoring the temperature changes in the exhaust gases. Why is temperature so critical? Because excessive heat can damage the catalytic converter and the particulate filter, and repairs can be extremely costly. When it detects abnormal temperatures, it immediately alerts the vehicle's computer, which then reduces engine power and adjusts the exhaust gas recirculation. Most importantly, during particulate filter regeneration, it precisely monitors the combustion temperature—if it's too low, the catalytic converter can clog; if it's too high, the filter element can melt. Either of these repair bills could cost as much as ten sets of tires!
A few days ago, this issue was still being debated in the car modification group. Simply put, it's the exhaust temperature guardian, and its location varies by vehicle type: diesel vehicles prefer to install it before and after the particulate filter, while gasoline vehicles usually place it behind the turbo. Its core mission is to protect two delicate components: the three-way catalytic converter and the particulate filter. Too low a temperature can clog the particulate filter (even regeneration won't help), and too high can burn it to ashes. Those of us who've modified the exhaust need to be especially careful—if this sensor's data is off, the least that can happen is a fault light and limited RPM, and at worst, it can crack a $2,000 three-way catalytic converter. Now, with China VI vehicles, it's even stricter: a temperature deviation of over 5℃ will limit torque.
