P0404

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Refer to Engine Controls Schematic IAC, Engine Oil Level, Engine Oil Pressure, EGR, EVAP Vent.

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the Exhaust Gas Recirculation (EGR) valve pintle position input in order to ensure that the valve responds properly to commands from the PCM. The PCM compares the actual EGR position with the desired EGR position when the valve is commanded open. If the difference between the actual EGR position and the desired EGR position is more than 15 percent, DTC P0404 will set.

CONDITIONS FOR RUNNING THE DTC
^ The ignition is ON.
^ The system voltage is between 10.0-18.0 volts.

CONDITIONS FOR SETTING THE DTC
^ The difference between the actual EGR position and the desired EGR Position is more than 15 percent.
^ The condition is present for more than 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic has been run and failed.
^ If equipped with traction control, the PCM will command the Electronic Brake And Traction Control Module (EBTCM) via the serial data circuit to turn OFF traction control, and the EBTCM will illuminate the TRACTION OFF lamp.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.

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.

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection - Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension.
^ Damaged harness - Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault.
^ PCM and engine grounds for clean and secure connections

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION
Numbers below refer to the step numbers on the Diagnostic Table:
2. 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, check for a poor connection at the PCM or the EGR valve. If the connections are OK and DTC P0404 continues to set, replace the EGR valve.
16. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.