P1406

Wiring Diagram:

P1406- EGR POSITION SENSOR PERFORMANCE
The exhaust gas recirculation (EGR) value consists of a pintle valve that moves by the use of an internal solenoid and an internal position sensor (potentiometer) used to determine pintle valve position. The ECM controls the solenoid by supplying it ground whenever exhaust gas needs to be recirculated into the intake manifold. The ECM monitors the EGR solenoid and position sensor circuit for correct voltage levels at certain times. Normal EGR sensor voltages range from 0.5-1.0 volts at a 0% commanded duty cycle up to 4.2-4.7 volts at a 100% commanded duty cycle DTC P1406 sets when the actual EGR sensor signal position differs from the ECM desired sensor position (based on the duty cycle of the solenoid) greater than a calibrated amount for a certain length of time.

DTC PARAMETERS
DTC P1406 will set it EGR sensor signal position differs from the ECM desired sensor position greater than +/- 20%( when:
^ Condition exists for longer than 10 seconds
^ EGR is being commanded On

DTC P1406 diagnostic runs continuously with engine running.

P1406 is a type B DTC

DIAGNOSTIC AIDS

IMPORTANT: If any other EGR sensor or EGR solenoid DTC (except P0401 or P0402) is also set, diagnose that DTC first.

Possible causes for DTC P1406:
^ Corrosion or resistance in the sensor connector or splice pack connectors. Normal EGR SENSOR values for a closed EGR valve should be within 0.5-1.0 volts.
^ ECM valve sticking.