P0406

DTC P0406 - EGR Valve Circuit Performance - Actual Position Less Than Commanded

Diagnostic Chart:

Schematic:

The Exhaust Gas Recirculation (EGR) solenoid and pintle valve assembly serve to reduce the temperature of combustion by introducing non-volatile exhaust gas into the combustion chambers. The EGR sensor signal voltage is constantly monitored. This circuit is bounded by upper and lower thresholds near 5 volts and zero volts. The voltage should never exceed the upper threshold, or be below the bottom threshold for correct operation. This DTC will set if the sensor signal voltage is less than the lower threshold for longer than 1 second.

DTC PARAMETERS
DTC P0406 will set when:
^ EGR Sensor Voltage greater than 4.82 volts for longer than 1 second
^ Engine is running
^ No battery voltage codes set

IMPORTANT: When this DTC sets, some EGR functions will be disabled for the remainder of that ignition cycle. When repairs are complete, codes must be cleared and ignition keyed Off for at least 10 seconds to allow proper operation.

DTC P0406 is a (type B) DTC.

DIAGNOSTIC AIDS
To locate an intermittent problem, use the Scan tool to monitor the actual EGR position with engine running.

Wiggling wires while monitoring the actual EGR position may locate the area where a short to ground exists.