Circuit/System Description

The exhaust gas temperature (EGT) sensors are variable resistors that measure the temperature of the exhaust gas at the inlet and outlet of the diesel oxidation catalyst as well as the outlet of the Diesel Particulate Filter (DPF). The Engine Control Module (ECM) supplies a bias 5-volt signal to the exhaust gas temperature sensor signal circuit and supplies a ground to the low reference circuit. The exhaust gas temperature information is used by the ECM during the particulate filter regeneration.

The following table illustrates the relationship between the temperature of the exhaust gas and the resistance and voltage of the exhaust gas temperature sensor.