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. The PCM will also monitor the position of the sensor in relation to its duty cycle, commanded On-time. DTC P1404 sets when the EGR sensor signal voltage is above the calibrated voltage value when the valve is commanded closed.

DTC P1404 will set if the actual EGR position is greater than 4 percent when:

OR

The actual EGR position is greater than 7.8 percent when:

DTC P1404 diagnostic runs continuously once the above conditions have been met and the engine is running.

DTC P1404 is a type A DTC.

If DTC P0403 or P1403 is set, diagnose that DTC first. A diagnosed EGR solenoid fault will cause this DTC to set.

Use a scan tool to command the EGR SOLENOID ON (pulse width modulation - PWM), while monitoring the EGR SENSOR. The values for the EGR SENSOR at a commanded state of 0 percent and 70 percent should fall within these ranges:

0 percent commanded state equals 0.5-1 volts from EGR SENSOR.

70 percent commanded state equals 4.2-4.7 volts from EGR SENSOR.

An open in circuit 452 or short to voltage on circuit 1456 will set this DTC.

Debris or binding pintle shaft holding EGR valve open may also set this DTC.