ECD SYSTEM, Diagnostic DTC:P1426

DTC Code DTC Name
P1426 Differential Pressure Sensor Installation Error

DESCRIPTION

Refer to DTC P1427 Click here.

P1426
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Engine is running at 3000 rpm with no load for 10 seconds or more. The differential pressure sensor value is -3.5 kPa or less for 10 seconds or more (1 trip detection logic).

  • Incorrect arrangement of differential pressure sensor hose piping

  • Differential pressure sensor vacuum hose is clogged

  • Blockage in center exhaust pipe assembly (vacuum transmitting pipe)

  • Differential pressure sensor assembly

  • ECM

Tech Tips


  • DTC P1427 (Differential pressure sensor circuit low) and/or DTC P1428 (Differential pressure sensor circuit high) will be present if there is an open or short in the differential pressure sensor assembly circuit.

  • After confirming DTC P1426, check the differential pressure by selecting the following menus on the tester: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.

    Result
    Condition Differential Pressure Output Sensor Condition
    Ignition switch ON Approximately 0 kPa Normal
    Always -5 kPa or 100 kPa Open or short circuit
    3000 rpm (No engine load) Negative output Incorrect arrangement of hose piping

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P1426)


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the tester on.

    5. Enter the following menus: Powertrain / Engine and ECT / DTC.

    6. Read the DTCs.

      Result
      Result Proceed to
      DTC P1426 is output A
      DTC P1426 and other DTCs are output B

      Tech Tips

      If codes other than P1426 are output, perform troubleshooting for those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CHECK CONNECTION OF VACUUM HOSE (DIFFERENTIAL PRESSURE SENSOR ASSEMBLY - CATALYST CONVERTER)


    1. Check if vacuum hose routing between the differential pressure sensor assembly and the catalyst converter is correct.

    2. Check that there is no exhaust gas leakage between the differential pressure sensor assembly and the catalyst converter.


    NG

    RECONNECT VACUUM HOSE

    OK

  3. CHECK BLOCKAGE OF VACUUM HOSE AND CATALYST CONVERTER

    CAUTION:

    Be careful of being burned by exhaust gases during the following inspection.


    1. Disconnect the vacuum hoses (both upstream and downstream) on the differential pressure sensor assembly.

    2. Start the engine.

    3. Check if there are exhaust gas pulsations from both vacuum hoses during idling.


    NG

    REPLACE CLOGGED PARTS

    OK

  4. READ VALUE USING INTELLIGENT TESTER (DIFFERENTIAL PRESSURE)


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON and turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.

    5. Check that differential pressure is within the specification below.

      OK
      Condition Differential Pressure Output Sensor Condition
      Ignition switch ON Approximately 0 kPa Normal

    NG

    REPLACE DIFFERENTIAL PRESSURE SENSOR ASSEMBLY Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here