Exhaust Gas Temperature (EGT) Sensor
The EGT sensor is a resistance temperature detector (RTD) type sensor. The EGT sensor is an input to the PCM and measures the temperature of the exhaust gas passing through the exhaust system. The electrical resistance of the sensor increases as the temperature increases, and resistance decreases as the temperature decreases. The varying resistance changes the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature.
The PCM uses the input from 4 EGT sensors to monitor the exhaust gas temperature. For wide frame applications, the EGT sensors are placed in the following order:
- Before the oxidation catalytic converter (OC) (EGT11)
- Between the OC and selective catalytic reduction (SCR) catalyst (EGT12)
- Between the SCR catalyst and diesel particulate filter (EGT13)
- After the diesel particulate filter (EGT14)
For narrow frame applications, the EGT sensors are placed in the following order:
- Before the OC (EGT11)
- Between the OC and diesel particulate filter (EGT12)
- Between the diesel particulate filter and SCR catalyst (EGT14)
- After the SCR catalyst (EGT13)