EGR Valve Position Sensor: Description and Operation

The PCM monitors the input from the EGR valve pintle position to ensure that the valve responds properly to commands from the PCM, and to detect a fault if the pintle position sensor circuit is open or shorted. If the PCM detects an excessively low EGR Feedback signal voltage, DTC P0405 sets.

The linear EGR valve is controlled with an ignition positive driver and a ground circuit within the PCM. The PCM has the ability to detect an electrical malfunction in the ignition positive circuit or in the ground circuit. If an electrical malfunction occurs, DTC P0403 sets.

When the ignition switch is turned on, the PCM learns the EGR closed valve pintle position. When the PCM commands the EGR valve closed, the learned pintle position is compared to the actual EGR position. If the actual EGR position indicates that the EGR valve is still open, DTC P1404 sets.

When the PCM commands the EGR valve open, the actual EGR position is compared with the desired EGR position. If the actual EGR position is 15 percent less than the desired EGR position when the PCM is commanding the EGR valve opened, DTC P0404 sets.