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) which used to determine pintle valve position. The EGR solenoid receives power through the main relay when the ignition key is in the crank or run position. The ECM controls the EGR solenoid by supplying a ground to the EGR solenoid whenever exhaust gas needs to be recirculated into the intake manifold. The EGR sensor signal voltage operating range is between .14 - 4.82 volts. The ECM monitors the EGR solenoid control feedback and EGR sensor signal (valve position) circuits for correct voltage levels at certain times. DTC P1406 will set if the actual EGR sensor signal position differs from the ECM desired sensor position greater than a calibrated value for a certain length of time.

DTC P1406 will set if the actual EGR sensor signal position differs from the ECM desired sensor position greater than 20 % when:

DTC P1406 diagnostic runs continuously with the ignition On.

P1406 is a (type B) DTC

DTC P1406 sets when the EGR solenoid becomes slow to respond or begins to deviate from the ECM desired position.

Possible causes: