Error code P0407 is displayed and the check engine light is on - what does this mean?
With DTC P0407, the OBD system detects a problem with the exhaust gas recirculation valve (EGR valve), specifically a low voltage level in the sensor B circuit. This trouble code indicates a malfunction in the electrical system of the EGR valve, which means that exhaust gas recirculation cannot be monitored properly.
What can cause this error code?
- Defective EGR valve position sensor
- Damaged wiring to the EGR valve
- Corroded or loose plug connections
- Short circuit in the sensor cable
- Defective EGR valve itself
- Contamination or blockage of the EGR system
- Faulty engine control unit (ECM/PCM)
What symptoms occur in parallel with fault code P0407?
- Uneven idling: The engine runs unevenly or rough when idling
- Increased emission values: Poor emission values during the emissions test
- Loss of power: Noticeable reduction in engine performance
- Increased fuel consumption: Significantly higher gasoline or diesel consumption
- Starting problems: Difficulty starting the engine, especially in cold weather
- Knocking noises: Unusual engine noises while driving
How to fix the problem of error code P0407?
- The repair requires a systematic approach to identify and eliminate the cause.
- Inspection and replacement of the EGR valve position sensor including calibration of the new sensor via the diagnostic device
- Complete inspection and repair of the wiring to the EGR valve, including replacement of damaged cables and sealing of the connections
- Cleaning of all plug connections with contact spray and ensuring tight connections with new contact pins if required
- Replacement of the entire EGR valve in the event of mechanical defects and subsequent programming via OBD interface
- Thorough cleaning of the EGR system with special cleaner and replacement of the EGR seals
- Checking and, if necessary, replacing the engine control unit according to the manufacturer's specifications
FAQ - Frequently asked questions about DTC P0407
Can I continue driving with error code P0407?
Short journeys are possible, but the fault code should be rectified promptly. Driving longer distances can lead to increased emissions and engine damage.
How much does it cost to repair fault code P0407?
The costs vary between 150-800 euros, depending on the cause. A new EGR position sensor costs around 80-200 euros, a complete EGR valve 300-600 euros plus labor.
How do I recognize a defective EGR sensor with P0407?
Typical signs are rough idling, increased exhaust gas values and the engine control light. An EOBD diagnosis confirms the specific sensor defect.
Can I repair fault code P0407 myself?
You can carry out simple cleaning work and plug connections yourself. However, replacing sensors or the EGR valve requires specialist knowledge and special tools.
How long does it take to repair P0407?
Between 1-4 hours, depending on the cause. A simple sensor cleaning takes about an hour, while replacing the entire EGR valve can take up to four hours.
Does error code P0407 occur more frequently in certain weather conditions?
Yes, especially in cold and damp weather, corrosion and moisture in the electrical connections can trigger the code.