Exhaust gas recirculation (EGR / AGR)
P0403–P0406, P0409 and P2413: EGR control and sensors
These codes distinguish electrical actuation, sensor feedback and overall system performance. That explains why a general “EGR fault” message is not yet a diagnosis of a particular component.
At a glance
What the codes tell you
- P0403
- Exhaust gas recirculation—control circuit.
- P0404
- Exhaust gas recirculation—control circuit range/performance.
- P0405
- EGR sensor A—signal low.
- P0406
- EGR sensor A—signal high.
- P0409
- EGR sensor A—circuit.
- P2413
- Exhaust gas recirculation—system performance.
How the entries differ
- P0403 and P0404 concern the control circuit and its range or performance respectively.
- P0405, P0406 and P0409 concern EGR sensor A’s signal level or circuit.
- P2413 describes system performance without identifying an individual component.
What is not yet established
- Signal, circuit and system-performance codes are not interchangeable.
- The letter A is a standardised designation; its actual installation position must be established for the vehicle.
- The code describes the control unit’s assessment. It determines neither which component needs replacing nor the repair required.
- Manufacturer-specific descriptions, status, freeze-frame data and live readings can materially change the interpretation.
Diagnostic information that helps next
A reliable assessment does not consider the code in isolation. The following information turns a number into a fault condition that can be investigated:
- Full manufacturer-specific diagnostic description
- Power supply, ground, connectors and signal behaviour
- Actuator command and position feedback
- Air-mass, boost-pressure and accompanying faults from the same event
More codes for this system
Frequently asked questions about P0403, P0404, P0405, P0406, P0409, P2413
What do fault codes P0403, P0404, P0405, P0406, P0409, P2413 mean?
P0403: Exhaust gas recirculation—control circuit. P0404: Exhaust gas recirculation—control circuit range/performance. P0405: EGR sensor A—signal low. P0406: EGR sensor A—signal high. P0409: EGR sensor A—circuit. P2413: Exhaust gas recirculation—system performance.
Which component needs replacing for P0403?
The code does not determine that. The full diagnostic description, fault status, freeze-frame data, live readings and vehicle-specific system checks determine the appropriate repair.
What information helps with diagnosis?
Useful information includes Full manufacturer-specific diagnostic description, Power supply, ground, connectors and signal behaviour, Actuator command and position feedback, Air-mass, boost-pressure and accompanying faults from the same event.
Traceable sources
Sources and scope
The descriptions are our own factual explanations of standardised generic OBD definitions. Manufacturer-specific P1xxx codes and differing manufacturer descriptions are not given blanket interpretations here.