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

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

DESCRIPTION

The throttle control motor and throttle position sensor are built into the diesel throttle body assembly. The ECM opens and closes the throttle valve using the throttle control motor (rotary solenoid type actuator). Due to opening and closing the valve, the exhaust gas recirculation volume can be properly controlled. Also, engine vibration and noise will be reduced by closing the valve when the engine is stopped.

DTC No. DTC Detection Condition Trouble Area
P0488

  • When throttle valve remains closed despite ECM's signal to open valve

    (1 trip detection logic)

  • When throttle valve remains open despite ECM's signal to close valve

    (1 trip detection logic)

  • Throttle valve stuck

  • Throttle valve does not move smoothly

  • Open or short in throttle valve circuit

  • Open or short in throttle valve position sensor circuit

  • Throttle position sensor (diesel throttle body assembly)

  • ECM

Tech Tips

After confirming DTC P0488, check the throttle position.

Reference:
Condition Throttle Valve Position
Moment when accelerator pedal is further depressed or released at 3,000 rpm Opening angle varies smoothly

MONITOR DESCRIPTION

The ECM opens and closes the throttle valve by adjusting the current flowing to the rotary solenoid 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, and the ECM will determine that the throttle valve is malfunctioning and the ECM illuminates the MIL.

A01BFBRE08

WIRING DIAGRAM

A01BB21E01

INSPECTION PROCEDURE

Note

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

Tech Tips


  • DTC P0488 is set when the engine is warmed up, and 1 second or more passes after quickly accelerating the engine from idling.

  • Read freeze frame data using an intelligent tester. Freeze frame data record 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, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0488)


    1. Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester ON.

    3. Select the following menu items: Powertrain / Engine / DTC.

    4. Read DTCs.

      Result
      Display (DTC Output) Proceed To
      P0488 A
      P0488, P0122 and/or P0123 B

      Tech Tips

      If any DTCs other than P0488 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART

    A

  2. CHECK WHETHER DTC OUTPUT RECURS (DTC P0488)


    1. Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester ON.

    3. Select the following menu items: Powertrain / Engine / DTC / Clear.

    4. Clear DTCs.

    5. Start the engine and warm it up.

    6. Accelerate the engine quickly from idle to 3,000 rpm 3times.

    7. Select the following menu items: Powertrain / Engine / DTC.

    8. Read DTCs.

      Result
      Display (DTC Output) Proceed To
      P0488 A
      No output B

      Tech Tips

      The normal operation of the throttle valve is as follows.

      Reference:
      Condition Throttle Valve Position
      Moment when accelerator pedal is further depressed or released at 3,000 rpm Opening angle varies smoothly

    B

    CHECK FOR INTERMITTENT PROBLEMS

    A

  3. INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE CONTROL MOTOR POWER SOURCE)


    1. A01BCKPE04

      Disconnect the D48 throttle control motor connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage of the wire harness side connector.

      Standard voltage
      Tester Connection Specified Condition
      B (D48-2) - Body ground 11 to 14 V

    4. Check the resistance.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      RSC (D48-3) - Body ground Below 1 Ω

    5. Reconnect the throttle control motor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (THROTTLE CONTROL MOTOR - ECM)


    1. A01BHIRE11

      Disconnect the D48 throttle control motor connector.

    2. Disconnect the D3 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      DUTY (D48-1) - LUSL (D3-4) Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      DUTY (D48-1) or LUSL (D3-4) - Body ground 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reconnect the throttle control motor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE DIESEL THROTTLE BODY ASSEMBLY


    1. Replace the diesel throttle body assembly Click here.


    NEXT

  6. CHECK WHETHER DTC OUTPUT RECURS (DTC P0488)


    1. Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester ON.

    3. Select the following menu items: Powertrain / Engine / DTC / Clear.

    4. Clear DTCs.

    5. Start the engine and warm it up.

    6. Accelerate the engine quickly from idle to 3,000 rpm 3 times.

    7. Select the following menu items: Powertrain / Engine / DTC.

    8. Read DTCs.

      Result
      Display (DTC Output) Proceed To
      P0488 A
      No output B

    B

    SYSTEM OK

    A

    REPLACE ECM