Ford P0409 OBD-II Trouble Code Definition: P0409 Exhaust Gas Recirculation (EGR) (Sensor A) Circuit Malfunction P0409 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0409 Exhaust Gas Recirculation Sensor “A” Circuit What does the code mean? OBD-ii Code P0409 definition: The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting pulses […]