P0406 — Exhaust Gas Recirculation Sensor "A" Circuit High
Exhaust Gas Recirculation Sensor "A" Circuit High: the signal voltage is above the expected range. Without valid EGR feedback the ECU disables exhaust gas recirculation and may set further EGR codes.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Egr position sensor
- Egr sensor wiring
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Sensor circuit shorted to supply
- EGR position sensor failed
- Connector pins corroded - high contact resistance
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.