P0409Exhaust Gas Recirculation Sensor "B" Circuit High
The EGR position sensor A signal voltage is below the lower diagnostic threshold — open circuit, short to ground, or sensor fault. With no valid feedback, the ECU disables EGR and may set additional EGR codes.
Can I keep driving? With caution
You can drive to the shop, but do not postpone the repair. The problem may worsen and damage other components.
Sistema Afectado
Sistema de Escape · Catalizador y sensores O₂
La falla se localiza en la línea de escape: catalizador, sondas lambda (O₂) o sistema EGR.
Espacio para vendedores de repuestos
Aún no hay un anunciante en este espacio.
Possible Causes
The components or conditions that trigger this code
- 1Sensor circuit shorted to supply EGR position sensor B failed Connector pins corroded - high contact resistance
How to Fix It — Step by Step
Recommended diagnostic and repair procedure
- 1Difficulty: medium. Estimated time: 0.3-2 hours. Estimated cost: €60-€
- 2DIY possible
Note: This information is for general reference. For precise diagnostics and safety repairs, always consult a certified mechanic.
Estimated Cost
Approximate range in USD (varies by region and shop)
Varies by diagnosis
* Diagnosis only: $50–$150
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