P1404

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. When the ignition switch is turned ON, the PCM learns the EGR learned minimum position. The PCM compares the EGR learned minimum position to the EGR position sensor when the EGR valve is commanded closed. If the EGR position sensor indicates that the EGR valve is still open when the PCM is commanding the EGR valve closed, this DTC will set.

CONDITIONS FOR RUNNING THE DTC
System voltage greater than 10 volts.

CONDITIONS FOR SETTING THE DTC
^ EGR position sensor is 1.25 volts more than the EGR learned minimum position when the desired EGR position is commanded to 0 percent.
^ The above condition is present twice.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.

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 the following condition:

Excessive deposits on the EGR valve pintle or seat- Remove the EGR valve and check 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 11-18:

The numbers below refer to the step numbers on the diagnostic table:
2. This step verifies that the malfunction is present.
4. If DTC P1404 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 P1404 continues to set, replace the EGR valve.