ECD SYSTEM(w/o Glow Plug Controller), Diagnostic DTC:P0641

DTC Code DTC Name
P0641 Sensor Reference Voltage "A" Circuit / Open

DESCRIPTION

Refer to DTC P0236.

Click here

Refer to DTC P2122.

Click here

Refer to DTC P2454.

Click here

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0641

Sensor Reference Voltage "A" Circuit / Open

Supplied power (standard: 5 V) from the ECM to the accelerator pedal sensor, diesel turbo pressure sensor and differential pressure sensor are lower or higher than appropriate thresholds.

(1 trip detection logic)

  • Accelerator pedal sensor assembly (accelerator pedal position sensor)

  • Open or short in accelerator pedal position sensor circuit

  • Diesel turbo pressure sensor

  • Open or short in diesel turbo pressure sensor circuit

  • Differential pressure sensor

  • Open or short in differential pressure sensor circuit

  • ECM

Comes on

DTC stored
Table 1. DTC Detection Drive Pattern

DTC No.

DTC Detection Drive Pattern

P0641

Ignition switch ON

WIRING DIAGRAM

Refer to DTC P0236.

Click here

Refer to DTC P2122.

Click here

Refer to DTC P2454.

Click here

CAUTION / NOTICE / HINT

Note:

When replacing the ECM, perform ECM Initialization and Registration.

Click hereClick here

Tip:

  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing a new ECM, perform all of the initialization and registration procedures 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. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)

    1. Disconnect the accelerator pedal sensor 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

      A3-4 (VCPA) or A101-56 (VCPA) - Body ground

      Always

      10 kΩ or higher

      A3-6 (VPA) or A101-55 (VPA) - Body ground

      Always

      10 kΩ or higher

      A3-5 (EPA) or A101-57 (EPA) - Body ground

      Always

      10 kΩ or higher

      A3-1 (VCP2) or A101-53 (VCP2) - Body ground

      Always

      10 kΩ or higher

      A3-3 (VPA2) or A101-52 (VPA2) - Body ground

      Always

      10 kΩ or higher

      A3-2 (EPA2) or A101-54 (EPA2) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  2. CHECK TERMINAL VOLTAGE (VC VOLTAGE)

    A254580C01

    *a

    Front view of wire harness connector

    (to Accelerator Pedal Sensor Assembly)

    1. Disconnect the accelerator pedal sensor 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

      Condition

      Specified Condition

      A3-4 (VCPA) - A3-5 (EPA)

      Ignition switch ON

      4.5 to 5.5 V

      A3-1 (VCP2) - A3-2 (EPA2)

      Ignition switch ON

      4.5 to 5.5 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE ECMClick here

    OK

  3. CHECK HARNESS AND CONNECTOR (DIFFERENTIAL PRESSURE SENSOR - ECM)

    1. Disconnect the differential pressure sensor 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

      B131-2 (PEX) or A101-32 (PEX) - Body ground

      Always

      10 kΩ or higher

      B131-3 (VC) or A101-33 (VCPX) - Body ground

      Always

      10 kΩ or higher

      B131-1 (E2) or A101-34 (EPEX) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  4. CHECK TERMINAL VOLTAGE (VC VOLTAGE)

    A200310C04

    *a

    Front view of wire harness connector

    (to Differential Pressure Sensor)

    1. Disconnect the differential pressure sensor 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

      Condition

      Specified Condition

      B131-3 (VC) - B131-1 (E2)

      Ignition switch ON

      4.5 to 5.5 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE ECMClick here

    OK

  5. CHECK HARNESS AND CONNECTOR (DIESEL TURBO PRESSURE SENSOR - ECM)

    1. Disconnect the diesel turbo pressure sensor 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

      B126-2 (PIM) or A101-13 (PIM) - Body ground

      Always

      10 kΩ or higher

      B126-3 (VC) or A101-14 (VPIM) - Body ground

      Always

      10 kΩ or higher

      B126-1 (E) or A101-15 (EPIM) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  6. CHECK TERMINAL VOLTAGE (VC VOLTAGE)

    A200310C05

    *a

    Front view of wire harness connector

    (to Diesel Turbo Pressure Sensor)

    1. Disconnect the diesel turbo pressure sensor 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

      Condition

      Specified Condition

      B126-3 (VC) - B126-1 (E)

      Ignition switch ON

      4.75 to 5.25 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE ECMClick here

    OK

  7. REPLACE DIESEL TURBO PRESSURE SENSOR

    1. Replace the diesel turbo pressure sensor.

      Click hereClick here

    Result

    Proceed to

    NEXT
    NEXT

  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P0641)

    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 30 seconds or more.

    5. Turn the ignition switch to ON.

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

    7. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC is not output

      A

      DTC P0641 is output

      B
    A

    END

    B

  9. REPLACE DIFFERENTIAL PRESSURE SENSOR

    1. Replace the differential pressure sensor.

      Click hereClick here

    Result

    Proceed to

    NEXT
    NEXT

  10. CHECK WHETHER DTC OUTPUT RECURS (DTC P0641)

    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 30 seconds or more.

    5. Turn the ignition switch to ON.

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

    7. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC is not output

      A

      DTC P0641 is output

      B
    A

    END

    B

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLYClick here

  11. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  12. REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

    1. Replace the accelerator pedal sensor assembly.

      Click here

    Result

    Proceed to

    NEXT
    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.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 30 seconds or more.

    5. Turn the ignition switch to ON.

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

    7. Confirm that the DTC is not output again.

      Powertrain > Engine and ECT > Trouble Codes

    Result

    Proceed to

    NEXT
    NEXT

    END

  14. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here