ECD SYSTEM(w/ DPF), Diagnostic DTC:P0122, P0123

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

DESCRIPTION

The throttle position sensor is built into the diesel throttle body and detects the opening angle of the throttle valve. This sensor is an electronic sensor and uses Hall-effect elements.

When the throttle valve is fully closed, a voltage of approximately 0.7 V is applied to terminal VTA1 of the ECM. The voltage applied to terminal VTA1 of the ECM increases in proportion to the opening angle of the throttle valve and becomes approximately 3.9 to 4.2 V when the throttle valve is fully opened.

The ECM determines the vehicle driving conditions from the signals input to its VTA1 terminal. The data is one of the inputs used for EGR control, etc.

A01VE4FE03
*1 Magnet
*2 Hall IC
*3 Throttle Position Sensor
P0122
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch ON

Throttle position sensor output (VTA1) is less than 0.2 V for 3 seconds.

(1 trip detection logic)

  • Throttle position sensor

  • Open or short in VTA1 circuit

  • Open in VCTA circuit

  • ECM
P0123
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch ON

Throttle position sensor output (VTA1) is higher than 4.8 V for 3 seconds.

(1 trip detection logic)

  • Throttle position sensor

  • Open in ETA circuit

  • VCTA and VTA1 circuits are short-circuited

  • ECM
Related Data List
DTC No. Data List
P0122

  • Target Throttle Position

  • Actual Throttle Position

  • Throttle Sensor Volt %
P0123

Tech Tips


  • Throttle position sensor output voltage "Throttle Sensor Volt %" is converted using 5 V = 0 %.

  • If DTC P0122 or P0123 is stored, the following symptoms may appear:


    • Intake booming noise

    • Black smoke

    • Lack of power

    • Vibration at engine stop

    • Turbo overspeed, turbo damage

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.

A01VM3NE08

WIRING DIAGRAM

A01VIR8E04

CAUTION / NOTICE / HINT

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


    1. Disconnect the B29 diesel throttle body assembly connector.

    2. Disconnect the B104 ECM connector (for LHD).

    3. Disconnect the B103 ECM connector (for RHD).

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      B29-5 (VC) - B104-65 (VCTA) Always Below 1 Ω
      B29-6 (VTA) - B104-80 (VTA1) Always Below 1 Ω
      B29-3 (E2) - B104-112 (ETA) Always Below 1 Ω
      B29-5 (VC) or B104-65 (VCTA) - Body ground Always 10 kΩ or higher
      B29-6 (VTA) or B104-80 (VTA1) - Body ground Always 10 kΩ or higher
      B29-3 (E2) or B104-112 (ETA) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      B29-5 (VC) - B103-65 (VCTA) Always Below 1 Ω
      B29-6 (VTA) - B103-80 (VTA1) Always Below 1 Ω
      B29-3 (E2) - B103-112 (ETA) Always Below 1 Ω
      B29-5 (VC) or B103-65 (VCTA) - Body ground Always 10 kΩ or higher
      B29-6 (VTA) or B103-80 (VTA1) - Body ground Always 10 kΩ or higher
      B29-3 (E2) or B103-112 (ETA) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  2. CHECK TERMINAL VOLTAGE (VC VOLTAGE)


    1. A01VHNVE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Diesel Throttle Body Assembly)

      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
      B29-5 (VC) - B29-3 (E2) Ignition switch ON 4.5 to 5.5 V

    NG

    REPLACE ECM Click here

    OK

  3. REPLACE DIESEL THROTTLE BODY ASSEMBLY


    1. Replace diesel throttle body assembly Click here.

    2. Turn the ignition switch to ON.

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


    NEXT

  4. READ VALUE USING GTS (ACTUAL THROTTLE POSITION)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

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

    6. Start the engine and wait for 30 seconds or more.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Actual Throttle position.

    8. Check the movement of the throttle valve when the ignition switch is turned off from the engine idling.

      Tech Tips

      When reading the values of Data List, confirm that PM regeneration is not activating (value of "After Injection Period" is 0) by entering the following menus: Powertrain / Engine and ECT / Data List / After Injection Period.

      If PM regeneration is activating (value of "After Injection Period" is not 0), drive the vehicle until the PM regeneration is complete (value of "After Injection Period" becomes 0).

      Standard
      Condition GTS Display
      Idling 10 to 100%
      Ignition switch off from engine idling Changes to 0% once, then return to 100%

    OK

    END

    NG

  5. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  6. REPAIR OR REPLACE HARNESS OR CONNECTOR


    NEXT

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

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

    6. Start the engine and wait for 30 seconds or more.

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

    8. Confirm that the DTC is not output again.


    NEXT

    END