Test Description

The numbers below refer to the step number in the diagnostic procedures.

1. 2
   
   This step verifies that the malfunction is present.
2. 3
   
   If DTC P0404 will only set under certain conditions, the malfunction may be intermittent. See DIAGNOSTIC AIDS . If an intermittent wiring problem is not present, test for a faulty connection at the PCM or EGR valve. If connections are okay and DTC P0404 continues to set, replace EGR valve.
3. 4
   
   When using the scan tool to increment the EGR valve, increment the valve to 10 percent then to 0 percent. Repeat this process to see if the test light turns ON then OFF. If the test light does not turn ON, the EGR solenoid high control circuit is open or shorted to ground.