P0404

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the Exhaust Gas Recirculation (EGR) valve pintle position input to ensure that the valve responds properly to commands from the PCM. The PCM compares the EGR position sensor with desired EGR position when the valve is commanded open. If the difference between the EGR position sensor and Desired EGR Position is more than 15 percent this DTC will set.

CONDITIONS FOR RUNNING THE DTC
^ The system voltage is greater than 10 volts.
^ EGR valve is enabled.

CONDITIONS FOR SETTING THE DTC
^ The difference between the EGR position sensor and the desired EGR position is more than 15 percent.
^ The condition is present for more than 25 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ First failure:
- The MIL is not turned ON.
- A DTC is stored in memory under Failed Last Test.
- The Failure Records are stored.
^ Second consecutive drive cycle with a failure:
- The MIL is turned ON.
- A DTC is stored in memory under history.
- The Freeze Frame data is stored.
- The Failure Records are stored.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after the third consecutive trip the diagnostic has run and passed.
^ The history DTC will clear if the fault conditions have not been detected for 40 warm-up cycles.
^ A scan tool can be used to clear DTC information.

DIAGNOSTIC AIDS
Inspect for excessive deposits on the EGR pintle or seat. Remove the EGR valve and inspect for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-10:

Steps 11-17:

The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies that the malfunction is present.
3. If DTC P0404 will only set under certain conditions, the malfunction may be intermittent. Refer to Diagnostic Aids. If an intermittent wiring problem is not present, test for a faulty connection at the PCM or the EGR valve. If the connections are OK and DTC P0404 continues to set, replace the EGR valve.