Circuit Description

The exhaust gas recirculation (EGR) valve position sensor is monitored by the engine control module (ECM). The 5-volt reference circuit, low reference circuit and the EGR valve position signal circuit are used by the ECM to determine the EGR valve position. The ECM compares the EGR Position Sensor parameter with the Desired EGR Position parameter when the valve is commanded open or closed. If the ECM detects a calibrated difference between the EGR Position Sensor parameter and Desired EGR Position parameter for a calibrated amount of time, DTC P0404 sets.