ECD SYSTEM, Diagnostic DTC:P2BAB

DTC Code DTC Name
P2BAB NOx Exceedance - Incorrect EGR Flow

DESCRIPTION

The EGR system recirculates exhaust gases, in order to suit every driving condition. The recirculated gas mingles with intake air, therefore the EGR system can slow combustion speed and keep the combustion temperature down. This helps reduce NOx emission.

In order to increase EGR circulation efficiency, the ECM adjusts the lift amount of the EGR valve assembly and throttle valve angle.

DTC No. DTC Detection Condition Trouble Area
P2BAB

EGR air flow rate less than the specified value when following conditions (a), (b), (c), (d), (e) and (f) are met:

(2 trip detection logic)

(a) Engine speed is 1400 to 2400 rpm

(b) Fuel quantify is 25 to 45 mm3/st

(c) Engine running condition is stable

(d) EGR valve assembly opening angle is 5% or more

(e) Exhaust brake system does not operate

(f) Mass air flow meter sub-assembly circuit malfunction, EGR valve assembly circuit malfunction, manifold absolute pressure sensor circuit malfunction and intake air temperature sensor (after turbocharged) circuit malfunction are not detected

  • EGR valve assembly stuck

  • EGR valve assembly does not move smoothly

  • EGR valve assembly deposit

  • EGR valve assembly passage deposit

  • EGR cooler sub-assembly

  • Air intake system (leaks or blockages)

  • Exhaust gas leaks

MONITOR DESCRIPTION

If the EGR valve assembly is forcibly operated but the intake air amount does not vary, the ECM determines that the EGR valve assembly is malfunctioning. The ECM then illuminates the MIL.

WIRING DIAGRAM

Refer to DTC P0405 Click here.

INSPECTION PROCEDURE

Note

After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

Tech Tips


  • When this DTC is stored the vehicle enters fail-safe mode, in which the MIL blinks and the ECM measures elapsed time until an idle signal has been input or engine speed is below 200 rpm after 36 hours, after which engine output is limited to 75%.

  • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, as well as other data recorded at the time of a malfunction.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2BAB)


    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 P2BAB is output A
      DTC P2BAB and other DTCs are output B

      Tech Tips

      If any DTCs other than P2BAB are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CHECK FOR EXHAUST GAS LEAKS


    1. Check for exhaust gas leaks.

      Result
      Result Proceed To
      Exhaust gas leaks out from exhaust system A
      No leaks B

    B

    CHECK AIR INTAKE SYSTEM (AIR LEAKS AND BLOCKAGES) Click here

    A

  3. REPAIR EXHAUST GAS LEAK POINT


    1. Repair or replace the malfunctioning part in exhaust system.


    NEXT

  4. CHECK AIR INTAKE SYSTEM (AIR LEAKS AND BLOCKAGES)


    1. Check for air leaks and blockages in the air intake system.

      Result
      Result Proceed To
      Leaks or blockages exist in the air intake system A
      No leaks and blockages in the air intake system B

      Tech Tips


      • Check for abnormal disconnection, pipe and hose squashing, and any damages in the air intake system.

      • Using your hand, check whether the pipes and hoses in the air intake system are securely connected.

      • Applying soapy water and revving the engine, air leaks from the air intake system can be checked.

      • Check for any modifications in the air intake system made by the user.


    B

    INSPECT EGR VALVE ASSEMBLY Click here

    A

  5. REPAIR OR REPLACE AIR INTAKE SYSTEM


    1. Repair or replace the malfunctioning part in the air intake system.


    NEXT

  6. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly.

    2. Inspect the EGR valve assembly.


      1. Visually check the EGR valve assembly for deposits.

        OK
        No deposits around the EGR valve.

      2. Visually check that there is no gap between the valve and body.

        OK
        No gap between the valve and body.
        Result
        Result Proceed To
        NG A
        OK B

    3. Reinstall the EGR valve assembly.


    B

    CHECK FOR BLOCKAGE IN EGR GAS PASSAGE (EXHAUST MANIFOLD - EGR COOLER - EGR VALVE ASSEMBLY) Click here

    A

  7. REPLACE EGR VALVE ASSEMBLY


    1. Replace the EGR valve assembly Click here.


    NEXT

  8. CHECK FOR BLOCKAGE IN EGR GAS PASSAGE (EXHAUST MANIFOLD - EGR COOLER - EGR VALVE ASSEMBLY)


    1. Check for blockage in the EGR gas passage from the exhaust manifold, through the EGR cooler sub-assembly to the EGR valve assembly.

      OK
      No blockage in the EGR gas passage.
      Result
      Result Proceed To
      NG A
      OK B

    B

    CHECK WHETHER DTC OUTPUT RECURS Click here

    A

  9. REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA


    1. Repair or replace the malfunctioning parts, component and area.


    NEXT

  10. CHECK WHETHER DTC OUTPUT RECURS


    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. Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F).

    6. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed, Injection Volume, Engine Load and EGR Lift Sensor Volt %.

    7. Drive the vehicle with the following conditions met for 30 seconds or more.

      Engine Speed: 1400 to 2400 rpm

      Injection Volume: 25 to 45 mm3/st

      Engine Load: Constant

      EGR Lift Sensor Volt %: 5 % or more

      Tech Tips

      Refer to the Freeze Frame Data recorded when the DTC was detected.

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

    9. Read the DTC.

      Result
      Result Proceed To
      DTC P2BAB is output A
      DTC is not output B

    B

    END

    A

  11. REPLACE EGR COOLER SUB-ASSEMBLY


    1. Replace the EGR cooler sub-assembly Click here.


    NEXT

  12. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    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. Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F).

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed, Injection Volume, Engine Load and EGR Lift Sensor Volt %.

    6. Drive the vehicle with the following conditions met for 30 seconds or more.

      Engine Speed: 1400 to 2400 rpm

      Injection Volume: 25 to 45 mm3/st

      Engine Load: Constant

      EGR Lift Sensor Volt %: 5 % or more

      Tech Tips

      Refer to the Freeze Frame Data recorded when the DTC was detected.

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

    8. Confirm that the DTC is not output again.

      Tech Tips

      If the DTC is output again, the mass air flow meter sub-assembly may be malfunctioning.


    NEXT

    END