ECD SYSTEM, Diagnostic DTC:P0120/41, P0122/41, P0123/41

DTC Code DTC Name
P0120/41 Throttle Pedal Position Sensor / Switch "A" Circuit Malfunction
P0122/41 Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input
P0123/41 Throttle / Pedal Position Sensor / Switch "A" Circuit High Input

DESCRIPTION

The throttle position sensor is mounted on the diesel throttle body and detects the opening angle of the throttle valve. This sensor is electronically controlled and uses Hall-effect elements.

The ECM judges the vehicle's driving conditions from the signals input to its VLU terminal. The data is one of the conditions for EGR control, etc.

A01BCIME01
DTC No. DTC Detection Condition Trouble Area
- Condition of DTC P0120/41, P0122/41 or P0123/41 continues for 3 seconds (open or short in throttle position sensor circuit) -
P0120/41

Throttle position sensor output (VLU) flutters up and down beyond normal operating range

(less than 0.2 V or more than 4.8 V)

(1 trip detection logic)

  • Open or short in throttle valve position sensor circuit

  • Throttle position sensor

  • ECM
P0122/41

Throttle position sensor output (VLU) is less than 0.2 V

(1 trip detection logic)

  • Throttle position sensor

  • Open or short in VLU circuit

  • Open in VC circuit

  • ECM
P0123/41

Throttle position sensor output (VLU) is more than 4.8 V

(1 trip detection logic)

  • Throttle position sensor

  • Open in E2 circuit

  • VC and VLU circuits are short-circuited

  • ECM

MONITOR DESCRIPTION

When the output voltage of the throttle position sensor deviates from the normal operating range (between 0.2 V and 4.8 V) for more than 3 seconds, the ECM interprets this as a malfunction of the sensor circuit and illuminates the MIL.

A01BCSBE01

WIRING DIAGRAM

A01BF1HE01

INSPECTION PROCEDURE

Note

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

Tech Tips


  • If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.

  • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)


    1. A01BF0WE01

      Disconnect the D3 and D1 ECM connectors.

    2. Disconnect the D50 throttle position sensor connector.

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

      Standard resistance
      Tester Connection Specified Condition
      D1-18 (VC) - D50-1 (VC) Below 1 Ω
      D3-29 (VLU) - D50-3 (VTA) Below 1 Ω
      D1-28 (E2) - D50-2 (E2) Below 1 Ω
      D1-18 (VC) or D50-1 (VC) - Body ground 10 kΩ or higher
      D3-29 (VLU) or D50-3 (VTA) - Body ground 10 kΩ or higher
      D1-28 (E2) or D50-2 (E2) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  2. CHECK ECM TERMINAL VOLTAGE (VC TERMINAL)


    1. A01BBQQE01

      Disconnect the D50 sensor connector.

    2. Turn the ignition switch ON.

    3. Measure the voltage of the ECM connector.

      Standard voltage
      Tester Connection Specified Condition
      D1-18 (VC) - D1-28 (E2) 4.5 to 5.5 V

    NG

    REPLACE ECM

    OK

  3. REPLACE DIESEL THROTTLE BODY ASSEMBLY


    NEXT

  4. CHECK IF DTC OUTPUT RECURS


    1. Clear the DTC(s) Click here.

    2. Start the engine.

    3. Let the engine idle for 60 seconds.

    4. Repeat quick engine revving to 2,500 rpm for 30 seconds.

    5. Read the DTC(s). Click here

      Result
      Display (DTC Output) Proceed to
      P0120/41, P0122/41 and/or P0123/41 A
      No output B

    B

    END

    A

    REPLACE ECM