EGR System Diagnostics

The PCM monitors the internal FOR valve solenoid (DTC P0403 and P1403) and position sensor (DTC P0405 and P01404) for low and high voltage faults. The PCM also monitors the FOR valve for a closed position error (P1404) and for a rational check of the valve position (P0404). A rational check of the valve position ensures the commanded duty cycle % the PCM is commanding correlates to a correct position the sensor is indicating.