GM Service Manual Online
For 1990-2009 cars only

Object Number: 871361  Size: MF

The exhaust gas recirculation (EGR) valve 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 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 P0403 sets when the EGR solenoid is commanded OFF and the feedback voltage at the PCM is high.

DTC Parameters

DTC P0403 will set if EGR solenoid feedback voltage is greater than 3.5 volts with EGR solenoid commanded OFF when:

    • The condition exists for longer than 0.5 seconds.
    • The ignition is ON.

DTC P0403 diagnostic runs continuously with ignition ON and EGR solenoid commanded OFF.

DTC P0403 is a type D DTC.

Diagnostic Aids

To locate an intermittent problem, use a scan tool to monitor the EGR SOLENOID - OPEN or EGR SOLENOID - HIGH VOLT test with ignition ON, engine OFF. When a fault (open or short to voltage) exists, the scan tool will display TEST FAIL for both tests.

The tests will fail only when the device is being commanded OFF and the voltage at the PCM is high. The tests update every 100 ms whenever the ignition is turned ON and the device is being commanded OFF via the scan tool or PCM.

The EGR solenoid resistance is 7-11 ohms.


Object Number: 875731  Size: FP