Theory Of Operation

WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The Exhaust Gas Recirculation Temperature Sensor is a variable resistor sensor and is used to measure the temperature of the EGR gas flow after it exits the EGR Cooler. The Powertrain Control Module (PCM) supplies 5-Volts to the exhaust gas recirculation temperature signal circuit. The PCM monitors the change in voltage caused by changes in the resistance of the sensor to determine the coolant temperature. The exhaust gas recirculation temperature value is used by the PCM for the engine protection system, and engine emissions control. This fault code is set active if the sensor signal voltage is above or below the normal operating range for the sensor and the PCM has commanded the EGR valve open. This fault code will not be set active if the PCM has commanded the EGR valve closed. The PCM will illuminate the Malfunction Indicator Lamp (MIL) after the diagnostic runs and fails in two consecutive drive cycles. During this time the EGR valve will be closed. The PCM turns off the MIL when the diagnostic runs and passes in four consecutive drive cycles.