Powertrain

P1404 - FAULT CODE - OBD2

Table Of Contents

    Description of DTC code P1404 Generic

    DTC P1404 OBD2 is a manufacturer-specific code that is set when the actual position of the EGR (Exhaust Gas Recirculation) valve pintle does not match the position the PCM expects to see when the valve is closed. About this code, it has to do with a problem in the position of the valve stem at startup, rather than the amount of exhaust recirculated into the system.

    The electronic EGR valve has a built-in position sensor that notifies the PCM of the location or position of the valve shaft. This data is the result of varying signal voltages that have changed between 0.1 and 0.3 volts when the valve is fully closed. If the valve is fully open, it has 5 volts. In practice, the PCM learns the valve closed signal voltage value when the circuits on a new vehicle are first activated. Such value is retained in the PCM as a reference value, which is compared to values after the closed position each time the ignition is turned on.

    The PCM monitors the EGR valve shaft position to check that it remains within the range necessary for proper operation. If it detects a voltage from the closed position sensor which does not match expected levels, the P1404 OBDII code will be set.

    Symptoms of fault code P1404 Generic

    • Check Engine light illuminated.
    • Difficult to start the engine.
    • Loss of engine power.
    • The idle speed is irregular.
    • The motor locks up unpredictably.
    • When accelerating or increasing the engine load, engine knocking occurs.
    • Emission levels are increased by the exhaust stream.

    Causes of OBD2 P1404 Generic

    The reasons for storing the P1404 OBD2 diagnostic code are:

    • The system circuit may have damage to the wires or connectors.
    • The Exhaust Gas Recirculation may be defective.
    • The moving parts of the EGR valve may have excessive wear.
    • The PCM may be faulty or damaged.

    Possible solutions of the DTC code P1404 Generic

    The steps to solve the P1404 OBDII fault code are as follows:

    • Consult the service manual to access the TSBs.
    • Turn on the ignition switch without starting the engine, and use a scanner to observe the position of the EGR valve shaft. Consult the specifications for the exact voltage to be applied to your vehicle. If the difference shown on the scan tool exceeds the allowable difference, check it is not because of obstructions that avoid the valve from closing completely. Make the necessary corrections.
    • Check the condition of wires, connectors, and other electrical components in the EGR valve circuit. Repair or replace any of these that are damaged.
    • Unplug the EGR connector and check if the signal voltage is equal to zero. If it is higher, check the resistance, reference voltage, continuity, and signal ground to check there is no short circuit to power. Compare the readings obtained with those specified by the manufacturer. If you find any differences, make the appropriate corrections.
    • Check the EGR valve, and check that it is not blocked by carbon deposits or other elements. If you observe wear in its moving parts, you must replace the valve.

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