Definition and Operation of the EGTS (Exhaust Gas Temperature Sensor)
The EGTS detects exhaust gas temperature, converts it into a voltage, and sends that voltage signal to the engine control unit (ECU) to monitor engine conditions and effectively reduce emissions.
In petrol engines, if the sensor detects excessive temperatures, the ECU will reduce the temperature by lowering the boost pressure. In diesel engines, the sensor is used to monitor the temperature of the diesel particulate fi lter (DPF) to determine the exact temperature for regeneration.
Where are EGTS sensors located in the vehicle?
EGT sensors can be found at multiple points in the vehicle’s exhaust system. As they’re used to monitor exhaust gas temperatures and protect critical systems from overheating or failure, these sensors are generally located near these critical system components. For example, one or more EGT sensors may be located near the EGR valve, turbocharger and diesel particulate filter to ensure proper system effi ciency. 
A – Before and after the turbocharger (Turbo)
The EGT sensor fi tted around the turbocharger verifi es that the component temperature has dropped to around 150°C to 200°C for proper operation, while also monitoring the temperature of the component for overheating.
B – Before and after the diesel oxidation catalyst (DOC)
El sensor EGT alrededor del catalizador de oxidación diésel es para monitorear la temperatura de escape de entrada con una temperatura mínima de 200°C para comenzar a funcionar. Mientras tanto, monitorear la salud del componente, como DOC obstruido y en caso de sobrecalentamiento.
C – Before and after the Diesel Particulate Filter (DPF)
El sensor EGT alrededor del filtro de partículas diésel (DPF) es para verifi car que el proceso de regeneración del DPF esté completo y sea efectivo. Mientras tanto, monitorear la salud del componente, como DPF obstruido y en caso de sobrecalentamiento.
D – Before and after selective catalytic reduction (SCR)
The EGT sensor fi tted around the selective catalytic reduction (SCR) monitors the temperature of the inlet exhaust, which requires a temperature of around 200°C to 400°C to start working, and that the outlet exhaust has been properly treated.
Faulty temperature sensors can cause:
- Unnecessary filter regeneration, resulting in a reduction in its service life.
- Energy losses if the sensor fails to detect the filter saturation level.
- Particulate filter warning light on the instrument panel and flashing glow plug warning light.
- Deterioration of turbocharger, DOC, SCR, and DPF components.
- Increase in oil consumption
- Increased CO, NOx, and HC emission levels.
