ECD SYSTEM, Diagnostic DTC:P1120

DTC Code DTC Name
P1120 Throttle / Pedal Position Sensor/Coolant Flow Control Valve Position Sensor Circuit

DESCRIPTION

Tech Tips


  • This is the repair procedure for the accelerator pedal position sensor.

  • The electrical throttle system does not use a throttle cable.

  • The accelerator pedal position sensor is a non-contact type.

The accelerator pedal position sensor is mounted in the accelerator pedal to detect the opening angle of the accelerator pedal. Since this sensor is electronically controlled with hall elements, accurate control and reliability can be obtained. It has 2 sensors to detect the accelerator position and a malfunction of the accelerator position sensor.

In the accelerator pedal position sensor, the voltage applied to pedal terminals VPA and VPA2 of the ECM changes between 0 V and 5 V, in proportion to the opening angle of the accelerator pedal. The VPA is a signal to indicate the actual accelerator pedal opening angle which is used for the engine control, and the VPA2 is a signal to indicate the information about the opening angle which is used for detecting a malfunction. The ECM judges the current opening angle of the accelerator pedal from these signals input from terminals VPA and VPA2, and the ECM controls the injection pump based on these signals.

B0028RDE39
DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P1120 Throttle / Pedal Position Sensor/Coolant Flow Control Valve Position Sensor Circuit

    Condition 1, 2, 3 or 4 continues for 2.0 seconds:

  1. VPA is 0.2 V or less and VPA2 is 0.5 V or less.

  2. VPA is 4.8 V or higher.

  3. VPA2 is 4.8 V or higher, and VPA is between 0.4 V and 3.45 V.

  4. The difference between VPA and VPA2 is 0.02 V or less.


    Condition 1 continues for 0.5 seconds:

  1. VPA is 0.2 V or less or VPA2 is 0.5 V or less.

  • Open or short in accelerator pedal position sensor circuit

  • Accelerator pedal rod assembly

  • ECM

 Comes on DTC stored

WIRING DIAGRAM

B002511E08
*a Accelerator Pedal Position Sensor

CAUTION / NOTICE / HINT

Tech Tips

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. READ VALUE USING GTS (ACCELERATOR POSITION)


    1. B00254HC03
      *1 Accelerator Pedal Assembly
      *a Depressed
      *b Released

      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 / Data List / Accel Sens. No.1 Volt % and Accel Sens. No.2 Volt %.


      Powertrain > Engine > Data List
      Tester Display
      Accel Sens. No.1 Volt %
      Accel Sens. No.2 Volt %

    4. Read the values.

      OK
      Check that the value displayed on the GTS changes by repeatedly depressing and releasing the accelerator pedal.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (ECM - ACCELERATOR PEDAL POSITION SENSOR) Click here

    OK

  2. READ DTC OUTPUT (ACCELERATOR PEDAL POSITION SENSOR DTC IS OUTPUT AGAIN)


    1. Connect the GTS to the DLC3.

    2. Clear the DTC.


      Powertrain > Engine > Clear DTCs

    3. Start the engine.

    4. Idle the engine for 15 seconds or more.

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


      Powertrain > Engine > Trouble Codes

    6. Read the DTC.

      Result
      Display (DTC output) Proceed to
      DTC P1120 is output again A
      No DTC output B

    A

    REPLACE ECM Click here

    B

    SYSTEM OK

  3. CHECK HARNESS AND CONNECTOR (ECM - ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the accelerator pedal position 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
      A41-1 (VCP2) - G121-23 (VCP2) Always Below 1 Ω
      A41-2 (EPA2) - G121-29 (EPA2) Always Below 1 Ω
      A41-3 (VPA2) - G121-28 (VPA2) Always Below 1 Ω
      A41-4 (VCPA) - G121-26 (VCPA) Always Below 1 Ω
      A41-5 (EPA) - G121-27 (EPA) Always Below 1 Ω
      A41-6 (VPA) - G121-20 (VPA) Always Below 1 Ω
      A41-1 (VCP2) or G121-23 (VCP2) - Body ground and other terminals Always 10 kΩ or higher
      A41-2 (EPA2) or G121-29 (EPA2) - Body ground and other terminals Always 10 kΩ or higher
      A41-3 (VPA2) or G121-28 (VPA2) - Body ground and other terminals Always 10 kΩ or higher
      A41-4 (VCPA) or G121-26 (VCPA) - Body ground and other terminals Always 10 kΩ or higher
      A41-5 (EPA) or G121-27 (EPA) - Body ground and other terminals Always 10 kΩ or higher
      A41-6 (VPA) or G121-20 (VPA) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT ECM


    1. B0026WSC62
      *a

      Front view of wire harness connector

      (to Accelerator Pedal Position Sensor)

      Disconnect the accelerator pedal position 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
      A41-1 (VCP2) - A41-2 (EPA2) Ignition switch ON 4.5 to 5.5 V
      A41-4 (VCPA) - A41-5 (EPA) Ignition switch ON 4.5 to 5.5 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE ECM Click here

    OK

  5. REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY


    1. Replace the accelerator pedal rod assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. READ DTC OUTPUT (ACCELERATOR PEDAL POSITION SENSOR DTC IS OUTPUT AGAIN)


    1. Connect the GTS to the DLC3.

    2. Clear the DTC.


      Powertrain > Engine > Clear DTCs

    3. Start the engine.

    4. Idle the engine for 15 seconds or more.

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


      Powertrain > Engine > Trouble Codes

    6. Read the DTC.

      Result
      Display (DTC output) Proceed to
      DTC P1120 is output again A
      No DTC output B

    A

    REPLACE ECM Click here

    B

    SYSTEM OK