СИСТЕМА ECD (для моделей с контроллером свечей накаливания), Diagnostic DTC:P21B4

DTC Code DTC Name
P21B4 Nox Adsorber Over Temperature Bank 1

DESCRIPTION

If the amount of accumulated PM in the DPF catalyst exceeds the threshold, the ECM performs PM regeneration. During PM regeneration, the temperature of the exhaust gas measured at the exhaust gas temperature sensor B1S1 and exhaust gas temperature sensor B1S2 will increase.

If the temperature of the exhaust gas measured at the exhaust gas temperature sensor B1S2 exceeds the threshold when PM regeneration is not being performed, the ECM will illuminate the MIL and store this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P21B4 Nox Adsorber Over Temperature Bank 1

The difference between the temperature of the exhaust gas measured by exhaust gas temperature sensor B1S1 and the estimated temperature calculated by the ECM is higher than the threshold (catalytic converter overheating).

(2 trip detection logic)

  • Exhaust gas temperature sensor B1S2

  • No. 2 exhaust manifold

  • ECM

 Comes on DTC stored
DTC Detection Drive Pattern
DTC No. DTC Detection Drive Pattern
P21B4 Vehicle being driven with warm engine
Related Data List
DTC No. Data List
P21B4

  • Exhaust Temperature B1S1

  • Exhaust Temperature B1S2

CAUTION / NOTICE / HINT

Note

When replacing the No. 2 exhaust manifold (catalyst), perform ECM Initialization and Registration.

Click here

Tech Tips

Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P21B4)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    4. Read the DTCs.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Result Proceed to
      DTC P21B4 is output A
      DTC P21B4 and other DTCs are output B

      Tech Tips

      If any DTCs other than P21B4 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. READ VALUE USING GTS (EXHAUST TEMPERATURE B1S1 AND EXHAUST TEMPERATURE B1S2)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / Exhaust Temperature B1S1 and Exhaust Temperature B1S2.


      Powertrain > Engine and ECT > Data List
      Tester Display
      Exhaust Temperature B1S1
      Exhaust Temperature B1S2

    4. Start the engine and allow it to idle until the engine coolant temperature reaches 75°C (167°F) or higher.

    5. Read the value.

      Tech Tips

      When reading the values of Data List, confirm that PM regeneration is not activating (value of "After Injection Period" is 0) by entering the following menus: Powertrain / Engine and ECT / Data List / After Injection Period.

      If PM regeneration is activating (value of "After Injection Period" is not 0), drive the vehicle until the PM regeneration is complete (value of "After Injection Period" becomes 0).

      Standard
      Data List Condition Standard Value
      Exhaust Temperature B1S1

      Idling with warm engine

      (Data List item "After Injection Period" is 0)

      		 80°C (176°F) or higher, and less than 220°C (428°F)
      Exhaust Temperature B1S2 80°C (176°F) or higher, and less than 220°C (428°F)
      Result
      Result Proceed to
      OK A
      Exhaust Temperature B1S1 value is malfunction B
      Exhaust Temperature B1S2 value is malfunction C

    B

    REPLACE EXHAUST GAS TEMPERATURE SENSOR B1S1 Click here

    C

    REPLACE EXHAUST GAS TEMPERATURE SENSOR B1S2 Click here

    A

  3. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE DPF REJUVENATE (PM))


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Start the engine.

    5. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the DPF Rejuvenate (PM) / Data List / Exhaust Temperature B1S1, Exhaust Temperature B1S2 and DPNR/DPF Status Reju(PM).


      Powertrain > Engine and ECT > Active Test
      Active Test Display
      Activate the DPF Rejuvenate (PM)
      Data List Display
      Exhaust Temperature B1S1
      Exhaust Temperature B1S2
      DPNR/DPF Status Reju(PM)

      Tech Tips

      After clearing DTCs, immediately enter the Active Test and then drive the vehicle.

    7. Perform the Active Test and then drive the vehicle at a constant engine speed of 2000 rpm or more (shift position: 3rd gear) at a vehicle speed between 65 to 100 km/h (40 to 62 mph).

      CAUTION:

      When performing the confirmation driving pattern, obey all speed limits and traffic laws.

      Tech Tips

      While the Active Test being performed, the accelerator pedal opening angle should be kept as constant as possible.

    8. Confirm that both Exhaust Temperature B1S1 and Exhaust Temperature B1S2 reach 250°C (482°F) or higher and the DPNR/DPF Status Reju(PM) turns from "Ready" to "Operate".

      Tech Tips


      • If the exhaust gas temperature does not reach the specified value, drive the vehicle again with a constant engine speed of 2000 rpm or more (shift position: 3rd gear) at a vehicle speed between 65 to 100 km/h (40 to 62 mph).

      • Perform the Active Test until one of the following conditions is met:


        1. DPNR/DPF Status Reju(PM) displays "Compl".

        2. DPNR/DPF Status Reju(PM) turns from "Operate" to "Ready" even if the cumulative time of "Operate" exceeds 35 minutes.

        3. DPNR/DPF Status Reju(PM) stays "Ready" even if both Exhaust Temperature B1S1 and Exhaust Temperature B1S2 have reached 250°C (482°F) or higher for more than 10 minutes with an engine speed of 2000 rpm or more. (PM regeneration could not operate.)

    9. Take a snapshot with the GTS when the Exhaust Temperature B1S1 and Exhaust Temperature B1S2 rise and become stable.

    10. Enter the following menus: Powertrain / Engine and ECT / Data List / DPNR/DPF Status Reju(PM).


      Powertrain > Engine and ECT > Data List
      Tester Display
      DPNR/DPF Status Reju(PM)

    11. Confirm the DPNR/DPF Status Reju(PM).

      Tech Tips


      • While performing PM regeneration, the DPNR/DPF Status Reju(PM) displays "Operate".

      • If the PM regeneration is stopped (DPNR/DPF Status Reju(PM) displays "Ready") because the exhaust gas temperature is reduced due to the driving conditions, the PM regeneration is restarted automatically (DPNR/DPF Status Reju(PM) displays "Operate") when the exhaust gas temperature is increased by driving with a high engine speed driving.

      • If the cumulative time of DPNR/DPF Status Reju(PM) at "Operate" exceeds 35 minutes, the Active Test will be canceled. In this case, the DPNR/DPF Status Reju(PM) turns to "Ready" and the Active Test / Activate the DPF Rejuvenate (PM) will be prohibited for one hour while engine running. Thus, perform the Active Test again after running the engine for one hour.

      DPNR/DPF Status Reju(PM) (Reference)
      GTS Display Status
      Standby Before entering "Activate the DPF Rejuvenate (PM)"
      Ready Enabling condition for "Activate the DPF Rejuvenate (PM)" is not sufficient
      Operate

      • PM regeneration is being performed.

      • If "Activate the DPF Rejuvenate (PM)" is not finished completely, the status turns to "Ready".

        For example, if the vehicle idles for more than 3 minutes while the PM regeneration is being performed, the exhaust gas temperature falls to outside of enabling condition and PM regeneration is stopped.

      • If "Activate the DPF Rejuvenate (PM)" is finished completely, the status turns to "Compl".
      Compl PM regeneration is completed (Amount of PM is 0 g)

    12. Check the value of the Data List items "Exhaust Temperature B1S2" in the snapshot that was taken while "Operate" was displayed for "DPNR/DPF Status Reju(PM)".

      Tech Tips

      As the temperature of the exhaust gas will decrease when the value of DPNR/DPF Status Reju(PM) changes to "Compl", make sure to read the Data List while "Operate" is displayed.

      Standard
      Dala List Condition Standard Value
      Exhaust Temperature B1S2 Value of DPNR/DPF Status Reju(PM) is "Operate". 500°C (932°F) or higher (maximum temperature is higher than 570°C (1058°F))
      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

  4. REPLACE NO. 2 EXHAUST MANIFOLD


    1. Replace the No. 2 exhaust manifold.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. PERFORM INITIALIZATION


    1. Clear the DPF deterioration record using the GTS.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 8 Click here

  6. REPLACE EXHAUST GAS TEMPERATURE SENSOR B1S1


    1. Replace the exhaust gas temperature sensor B1S1.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 8 Click here

  7. REPLACE EXHAUST GAS TEMPERATURE SENSOR B1S2


    1. Replace the exhaust gas temperature sensor B1S2.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  8. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

    6. Perform the simulation test.

    7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

    8. Confirm that the pending DTC is not output again.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Proceed to
      NEXT

    NEXT

    END