ECD SYSTEM, Diagnostic DTC:P0638

DTC Code DTC Name
P0638 Throttle Actuator Control Range / Performance Bank 1

DESCRIPTION

Refer to P0122 Click here.

DTC No. DTC Detection Condition Trouble Area
P0638

Internal error in diesel throttle body assembly output side for 2 seconds or more

(3 trip detection logic)

  • Diesel throttle body assembly

  • Open or short in diesel throttle body assembly circuit

  • Intake system

  • ECM

WIRING DIAGRAM

A01IU6VE01

INSPECTION PROCEDURE

Note

When replacing the ECM, the ECM needs Registration and Initialization Click here.

Tech Tips


  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • 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. PERFORM ACTIVE TEST USING GTS (ACTUATOR TEST OF FAN HIGH SPEED AND LOW SPEED)


    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 / Actuator Test of Fan High Speed and Actuator Test of Fan Low Speed.

      OK
      Cooling fan operates according to operation.

    NG

    REPLACE COOLING FAN SYSTEM Click here

    OK

  2. CHECK INTAKE SYSTEM


    1. Check for looseness or air leaks in the intake system after the diesel throttle body assembly.

      OK
      No looseness or air leaks.

    NG

    REPAIR OR REPLACE INTAKE SYSTEM Click here

    OK

  3. CHECK DIESEL THROTTLE BODY ASSEMBLY


    1. Check for excessive dirt or a mechanical malfunction in the diesel throttle body assembly.

      OK
      No mechanical malfunction or excessive dirt.

    NG

    REPAIR OR REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - 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
      G1-1 (VC) - C84-83 (VCTA) Always Below 1 Ω
      G1-3 (VTA) - C84-117 (VTA1) Always Below 1 Ω
      G1-2 (E2) - C84-81 (ETA) Always Below 1 Ω
      G1-4 (M+) - C84-50 (M+) Always Below 1 Ω
      G1-5 (M-) - C84-20 (M-) Always Below 1 Ω
      G1-1 (VC) or C84-83 (VCTA) - Body ground Always 10 kΩ or higher
      G1-3 (VTA) or C84-117 (VTA1) - Body ground Always 10 kΩ or higher
      G1-2 (E2) or C84-81 (ETA) - Body ground Always 10 kΩ or higher
      G1-4 (M+) or C84-50 (M+) - Body ground Always 10 kΩ or higher
      G1-5 (M-) or C84-20 (M-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (VC VOLTAGE)


    1. Disconnect the diesel throttle body assembly connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G1-1 (VC) - G1-2 (E2) Ignition switch ON 4.5 to 5.5 V

    NG

    REPLACE ECM Click here

    OK

  6. REPLACE DIESEL THROTTLE BODY ASSEMBLY


    1. Replace diesel throttle body assembly Click here.


    NEXT

  7. CHECK WHETHER DTC OUTPUT RECURS (DTC P0638)


    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs Click here.

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

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

    8. Read the DTCs.

      Result
      Result Proceed to
      No DTC output A
      DTC P0638 B

    B

    REPLACE ECM Click here

    A

    END

  8. REPLACE COOLING FAN SYSTEM


    1. Repair or replace the cooling fan system Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  9. REPAIR OR REPLACE INTAKE SYSTEM


    1. Repair or replace the malfunctioning parts of the intake system.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  10. REPAIR OR REPLACE DIESEL THROTTLE BODY ASSEMBLY


    1. Repair or replace the diesel throttle body assembly.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  11. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  12. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  13. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs Click here.

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

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

    8. Confirm that the DTC is not output again.


    NEXT

    END