For 1990-2009 cars

The exhaust gas recirculation (EGR) valve consists of a pintle valve which moves by the use of an internal solenoid and an internal position sensor (potentiometer) used to determine pintle valve position. The powertrain control module (PCM) controls the solenoid by supplying it ignition voltage whenever exhaust gas needs to be recirculated into the intake manifold. The PCM monitors the EGR solenoid and position sensor circuits for correct voltage levels at certain times. DTC P0405 sets when the EGR sensor signal voltage is below the calibrated voltage value.

### DTC Parameters

DTC P0405 will set if EGR sensor voltage is less than 0.35 volts when:

• | The condition exists for longer than 5 seconds.

• | The ignition voltage is greater than 11 volts.

• | The engine is running.

DTC P0405 diagnostic runs continuously with engine running and ignition voltage over 11 volts.

DTC P0405 is a type B DTC.

### Diagnostic Aids

Important: If DTC P1635 is set, diagnose that DTC first.

To locate an intermittent problem, use a scan tool to monitor EGR SENSOR voltage with ignition ON, engine OFF. Wiggling wires while watching for a change in EGR SENSOR voltage may locate the area where an open or short to ground in the wiring could lie.

Normal closed position values from the EGR sensor should never be less than the calibrated value listed under DTC parameters.

EGR is disabled for the entire ignition cycle if DTC P0405 fails within that ignition cycle.

PCM may command EGR solenoid ON at any engine coolant temperature (ECT) regardless of loop status.