What is an Exhaust Gas Temperature sensor? What are the signs of EGT sensor malfunctions? How does the EGT sensor function ?….
What is an Exhaust Gas Temperature Sensor?
EGT sensor is an acronym for exhaust gas temperature sensor. It measures the temperature of exhaust gases. This information is sent to the engine control unit (ECM/ECU), and can be used for various operations in gasoline and diesel-powered vehicles. This sensor allows for management of many engine system functions, including adjusting the temperature of catalytic converters, decreasing exhaust emissions, initiating the DPF (Diesel Particulate Filter), and preventing engine components from overheating.
How does the Exhaust gas temperature sensor work?
Engines today are more economical and environmentally friendly, yet they are also more powerful. To increase their power, small-volume engines can be equipped with supercharging or turbocharging systems. However, important components are reduced and the engine is subject to higher temperatures.
This has made the use of exhaust gas temperature sensor technology more complicated. EGT sensors are now a necessity in order to protect engine components.
Vehicles with either gasoline or diesel engines can use exhaust gas temperature sensor. Three or more EGT sensors may be installed to monitor exhaust gas temperature. One sensor is placed before the turbocharger and one before the DPF. The other is after the particulate filters.
There are two types: NTC (Negative temperature coefficient) and PTC [Positivetemperature coefficient] sensors. Both sensors are the same but the methods used to measure temperature are different. NTC sensors have high resistance to low temperatures. Higher temperatures cause the resistance to decrease. This means that the resistance decreases with temperature. PTC sensors respond directly to temperature. According to temperature, the resistance changes or increases. The sensor design will determine the range of possible measurements and the resistances to temperature. The voltage signal is sent by both sensors to inform the ECU of the status. The ECU interprets these signals to perform the required actions, according to pre-determined parameters.
Gasoline Engine EGT sensors
The main purpose of exhaust gas temperature sensors in gasoline engines is to prevent components from overheating. The turbocharger as well as the catalytic convert are critical components in this instance. The EGT sensor will detect excessive temperatures in these components and the ECU will take appropriate action to reduce the engine’s power and pressure boost.
Depending upon the setting of engine management, it can increase the amount and/or fuel consumption to cool down the catalytic Converter.
Diesel Engine EGT Sensors
Exhaust gas temperature sensors (DPF) are used in diesel engines to monitor temperature of the particulate filter. This is a way to verify that the temperature required for the regeneration is being provided.
Other functions of Exhaust gas temperature sensors
EGT sensors can also be used to lower nitrogen oxide (NOx), values. The temperature of the catalytic convert is controlled continuously to prevent overheating. Newly produced sensors have a measuring range of -40 to +900˚C.
In some EGR systems, temperature sensors can also be used. These sensors work basically the same as exhaust gas temperature sensors, but they are smaller and have a 400˚C lower maximum measurable temperature.
Is the EGT sensor located in the engine?
The exhaust gas temperature sensors’ mounting locations vary depending on the intended purpose. They are located at the inlets or outlets of the turbocharger and catalytic converters, DPF (Diesel Particulate Filter), and other components of the NOx-reduction system. It is dependent on the vehicle’s model that the entry locations and numbers are different.
What happens if an EGT sensor fails to work?
– DPF (Diesel Particulate Filter) clogged
– DPF regeneration processes take longer
– Incorrect DPF regeneration processes occur
– Fuel consumption is rising
Overheating can cause exhaust components and internal engine parts to fail.
– The Engine Failure Warning Lamp is now on
– The emission values are increasing
