P0404

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) controls the movement of the valve using the Exhaust Gas Recirculation (EGR) control circuit. The PCM monitors the pintle position input to make sure that the valve responds to the commands from the PCM. With the key turned ON, the PCM learns an EGR closed valve pintle position. When the PCM commands the valve closed, the PCM compares the learned closed EGR valve pintle position to the actual EGR position. If the actual EGR position indicates an open valve when the PCM has commanded the valve closed, DTC P0404 will set.

CONDITIONS FOR RUNNING THE DTC
^ System voltage is more than 11 volts.
^ DTC P0401 inactive
^ EGR is enabled

CONDITIONS FOR SETTING THE DTC
The actual EGR position is 20 percent less than the desired EGR position.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions. Intermittent Conditions

Check for excessive deposits on the EGR pintle or seat. Deposits may interfere with the EGR valve pintle extending completely. Deposits in the pintle seat area may cause the pintle to stick.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. Verifies that the malfunction is present.
3. Attempts to duplicate the malfunction using the stored failure conditions.