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ECD SYSTEM(w/o EGR System), Diagnostic DTC:P0488

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DTC Code DTC Name
P0488 Exhaust Gas Recirculation Throttle Position Control Range / Performance
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DESCRIPTION

The ECM opens and closes the throttle valve using a DC motor type actuator. Also, engine vibration and noise will be reduced by closing the valve when the engine is stopped.

Although the DTC title says "Exhaust Gas Recirculation Throttle Position Control Range / Performance", this DTC indicates that the throttle valve is malfunctioning.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0488 Exhaust Gas Recirculation Throttle Position Control Range / Performance The throttle actuator activation duty is more than specified value for 60 seconds (1 trip detection logic).

  • Throttle valve stuck

  • Throttle valve does not move smoothly

  • Open or short in throttle actuator circuit

  • ECM

 Comes on DTC stored
Table 1. Related Data List
DTC No. Data List
P0488

  • Target Throttle Position

  • Actual Throttle Position

  • Throttle Motor DUTY

  • Throttle Close Learning Val.
Table 2. Reference
Condition Throttle Valve Position
Moment when accelerator pedal is depressed further or released at 3000 rpm Throttle valve opening angle varies smoothly
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CONFIRMATION DRIVING PATTERN

DTC No. DTC Detection Drive Pattern
P0488

Perform the following repeatedly for 1 minute:

gradually raise the engine speed to 3000 rpm from idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state.
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MONITOR DESCRIPTION

The ECM opens and closes the throttle valve by adjusting the current flowing to the DC motor with a duty ratio. If the throttle valve does not move smoothly or is stuck, the duty ratio used during valve movement control increases or decreases greatly. The ECM will determine that the throttle valve is malfunctioning and illuminate the MIL.

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WIRING DIAGRAM

Refer to DTC P0122.

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CAUTION / NOTICE / HINT

Note:

  • When cleaning the diesel throttle body assembly, use a piece of cloth soaked with cleaning solvent. Spraying solvent directly onto these parts or soaking the parts in solvent may damage the parts.

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

Tip:

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.

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PROCEDURE


  1. Click here

    PERFORM ACTIVE TEST USING GTS (DIESEL THROTTLE TARGET ANGLE)


    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 / Active Test / Diesel Throttle Target Angle / Primary / Actual Throttle Position.


      1. Powertrain > Engine and ECT > Active Test
        Active Test Display
        Diesel Throttle Target Angle
        Data List Display
        Actual Throttle Position





    4. When changing the Active Test continuously value to 10, 30, 60, 90, 60, 30 and 10%, check that Actual Throttle Position smoothly changes to the set opening angle.

      OK
      Value smoothly changes to set opening angle.
      Result
      Proceed to
      OK
      NG

  2. Click here

    CHECK FOR DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY)


    1. Visually check for deposits in the diesel throttle body assembly. If there are deposits, clean the diesel throttle body assembly.

      Note:

      • When cleaning the diesel throttle body assembly, use a piece of cloth soaked with cleaning solvent. Spraying solvent directly onto these parts or soaking the parts in solvent may damage the parts.

      • Extreme care must be taken to prevent the removed deposits from falling into the engine unit during cleaning.

      Result
      Proceed to
      NEXT

  3. Click here

    INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE VALVE MOVEMENT)


    1. Using your finger, move the throttle valve from the fully open position to the fully closed position and check that it moves smoothly.

      OK
      Throttle valve moves smoothly.
      Note:

      Take care not to damage the throttle valve or valve housing.

      Result
      Proceed to
      OK
      NG

  4. Click here

    CHECK WHETHER DTC OUTPUT RECURS (DTC P0488)


    1. Start the engine and warm it up.

    2. Connect the GTS to the DLC3.

    3. Turn the GTS on.

    4. Take a snapshot with the GTS.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle / Primary / Actual Throttle Position.


      1. Powertrain > Engine and ECT > Active Test
        Active Test Display
        Diesel Throttle Target Angle
        Data List Display
        Actual Throttle Position





      Tip:

      The movement of the throttle valve can be determined by performing the following inspection.

    6. When changing the Active Test value continuously to 10, 30, 60, 90, 60, 30 and 10%, check that Actual Throttle Position smoothly changes to the set opening angle.

      OK
      Value smoothly changes to set opening angle.

    7. Perform the following repeatedly for 1 minute: gradually raise the engine speed to 3000 rpm from an idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state.

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

    9. Read the DTCs.


      1. Powertrain > Engine and ECT > Trouble Codes


      OK
      DTC is not output.
      Result
      Proceed to
      OK
      NG

  5. Click here

    REPLACE ECM


    1. Replace the ECM.

      Click here

      Result
      Proceed to
      NEXT

  6. Click here

    CHECK WHETHER DTC OUTPUT RECURS (DTC P0488)


    1. Start the engine and warm it up.

    2. Connect the GTS to the DLC3.

    3. Turn the GTS on.

    4. Take a snapshot with the GTS.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle / Primary / Actual Throttle Position.


      1. Powertrain > Engine and ECT > Active Test
        Active Test Display
        Diesel Throttle Target Angle
        Data List Display
        Actual Throttle Position





      Tip:

      The movement of the throttle valve can be determined by performing the following inspection.

    6. When changing the Active Test value continuously to 10, 30, 60, 90, 60, 30 and 10%, check that Actual Throttle Position smoothly changes to the set opening angle.

      OK
      Value smoothly changes to set opening angle.

    7. Perform the following repeatedly for 1 minute: gradually raise the engine speed to 3000 rpm from an idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state.

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

    9. Confirm that the DTC is not output.


      1. Powertrain > Engine and ECT > Trouble Codes


      Result
      Proceed to
      NEXT

    • NEXT

      END

  7. Click here

    REPLACE DIESEL THROTTLE BODY ASSEMBLY


    1. Replace the diesel throttle body assembly.

      Click here

      Result
      Proceed to
      NEXT

  8. Click here

    CHECK FOR DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY)


    1. Visually check for deposits in the diesel throttle body assembly. If there are deposits, clean the diesel throttle body assembly.

      Note:

      • When cleaning the diesel throttle body assembly, use a piece of cloth soaked with cleaning solvent. Spraying solvent directly onto these parts or soaking the parts in solvent may damage the parts.

      • Extreme care must be taken to prevent the removed deposits from falling into the engine unit during cleaning.

      Result
      Proceed to
      NEXT

  9. Click here

    INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE VALVE MOVEMENT)


    1. Using your finger, move the throttle valve from the fully open position to the fully closed position and check that it moves smoothly.

      OK
      Throttle valve moves smoothly.
      Note:

      Take care not to damage the throttle valve or valve housing.

      Result
      Proceed to
      OK
      NG

  10. Click here

    CHECK HARNESS AND CONNECTOR (DIESEL THROTTLE BODY ASSEMBLY - ECM)


    1. Disconnect the diesel throttle body assembly connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Y1-5 (VC) - C59-29 (VCVL) Always Below 1 Ω
      Y1-6 (VTA) - C59-21 (VLU) Always Below 1 Ω
      Y1-3 (E2) - C59-20 (EVLU) Always Below 1 Ω
      Y1-2 (M+) - C60-6 (M+) Always Below 1 Ω
      Y1-1 (M-) - C60-5 (M-) Always Below 1 Ω
      Y1-5 (VC) or C59-29 (VCVL) - Body ground and other terminals Always 10 kΩ or higher
      Y1-6 (VTA) or C59-21 (VLU) - Body ground and other terminals Always 10 kΩ or higher
      Y1-3 (E2) or C59-20 (EVLU) - Body ground and other terminals Always 10 kΩ or higher
      Y1-2 (M+) or C60-6 (M+) - Body ground and other terminals Always 10 kΩ or higher
      Y1-1 (M-) or C60-5 (M-) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the diesel throttle body assembly connector.

    5. Reconnect the ECM connector.

      Result
      Proceed to
      OK
      NG

  11. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.

      Result
      Proceed to
      NEXT