P1404

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

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 is turned ON, the PCM learns the EGR Closed Valve Pintle Position. The PCM compares the learned EGR closed valve pintle position to the Actual EGR position when the EGR valve is commanded closed. If the Actual EGR position indicates that the EGR valve is still open when the PCM is commanding the EGR valve closed, DTC P1404 will set.

CONDITIONS FOR RUNNING THE DTC
^ No TP, VSS, Misfire, AT, MAP, Idle Speed, Fuel Injector, ECT, CKP, or MAF Sensor DTCs set.
^ System voltage is between 10-16 volts.

CONDITIONS FOR SETTING THE DTC
^ EGR Feedback is 0.2 volt more than the EGR Closed Valve Pintle Position when the Desired EGR Position is commanded to 0 percent.
^ The above condition is present for longer than 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
^ 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 the following conditions:
^ 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.
^ Poor connections at PCM or EGR valve - Inspect harness connectors for:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal to wire connection
^ Damaged harness - Inspect the wiring harness for damage. If the wiring appears to be OK, connect a DMM and check for circuit continuity while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the malfunction.

TEST DESCRIPTION
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 DTC P1404 Diagnostic Aids. If an intermittent wiring problem is not present, inspect for a poor connection at the PCM or the EGR valve. If the connections are OK and DTC P1404 continues to set, replace the EGR valve.
14. 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.