Faulty Exhaust Gas Temperature Sensor (EGTS) 3
Exhaust Gas Temperature Sensor 3 harness is open or shorted
Exhaust Gas Temperature Sensor 3 circuit poor electrical connection
Excessive particulate matter buildup on sensor
Faulty Engine Control Module (ECM)
Engine Light ON (or Service Engine Soon Warning Light)
The Exhaust Gas Temperature Sensors (EGTS) are variable resistors that measure the temperature of the exhaust gas. The exhaust temperature sensor 1 is the first exhaust temperature sensor on the exhaust system, the following exhaust temperature sensors are counted upward from the engine outlet to the exhaust system end. The Engine Control Module (ECM) supplies 5 V to the exhaust gas temperature signal circuit and supplies a ground to the low reference circuit. The Exhaust Gas Temperature Sensor temperature information is used by the ECM during the exhaust gas particulate filter cleaning process. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the Exhaust Gas Temperature Sensor resistance has changed greater than a calibrated amount in less than 1 s.