DTC code
P0405
Exhaust Gas Recirculation Sensor A Circuit Low
Technical guide
Symptoms
- Check engine light
- failed emissions testing
- decreased performance
- reduced fuel economy
- engine pinging
Probable causes
- Faulty EGR valve position sensor
- defective EGR valve
- malfunctioning differential pressure feedback electronic (DPFE) sensor
- damaged or loose wiring/connectors
- ECM issues (rare)
Diagnostic steps
- Read all of the codes with a scan tool to see if there are others.
- Use the scan tool to force the EGR valve on.
- Disconnect the EGR harness.
- Using a multimeter, measure the wire running to the EGR valve — it should read around 5 volts.
- Check for shorts if reading shows 12 volts.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P0405
Nothing confirmed yet for this code. No guess is offered on purpose.
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