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ECD SYSTEM (w/ DPF), Diagnostic DTC:P2120, P2122, P2123, P2125, P2127, P2128, P2138

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DTC Code DTC Name
P2120 Throttle / Pedal Position Sensor / Switch "D" Circuit
P2122 Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input
P2123 Throttle / Pedal Position Sensor / Switch "D" Circuit High Input
P2125 Throttle / Pedal Position Sensor / Switch "E" Circuit
P2127 Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input
P2128 Throttle / Pedal Position Sensor / Switch "E" Circuit High Input
P2138 Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation
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DESCRIPTION

Tip:

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

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

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

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

In the accelerator pedal position sensor, the voltage applied to 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 engine control, and the VPA2 is a signal to indicate information about the opening angle which is used for detecting malfunctions. The ECM determines the current opening angle of the accelerator pedal using signals from terminals VPA and VPA2, and the ECM controls the throttle motor based on these signals.

Table 1. P2120
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Condition (a) continues for 0.5 seconds:

(1 trip detection logic)

(a) VPA is below 0.4 V and VPA2 is more than 2.7 deg, or VPA is higher than 4.8 V.

  • Accelerator pedal position sensor

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 2. P2122
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Conditions (a) and (b) continue for 0.5 seconds:

(1 trip detection logic)

(a) VPA is below 0.4 V.

(b) VPA2 is more than 2.7 deg.

  • Accelerator pedal position sensor

  • Open in VCPA circuit

  • VPA circuit open or shorted to ground

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 3. P2123
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Condition (a) continues for 2.0 seconds:

(1 trip detection logic)

(a) VPA is higher than 4.8 V.

  • Accelerator pedal position sensor

  • Open in EPA circuit

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 4. P2125
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Condition (a) continues for 0.5 seconds:

(1 trip detection logic)

(a) VPA2 is below 1.2 V and VPA is more than 2.7 deg, or VPA2 is higher than 4.8 V and VPA is higher than 0.4 V but below 3.45 V.

  • Accelerator pedal position sensor

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 5. P2127
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Conditions (a) and (b) continue for 0.5 seconds:

(1 trip detection logic)

(a) VPA2 is below 1.2 V.

(b) VPA1 is more than 2.7 deg.

  • Accelerator pedal position sensor

  • Open in VCP2 circuit

  • VPA2 circuit open or shorted to ground

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 6. P2128
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Conditions (a) and (b) continue for 2.0 seconds:

(1 trip detection logic)

(a) VPA2 is higher than 4.8 V.

(b) VPA is higher than 0.4 V but below 3.45 V.

  • Accelerator pedal position sensor

  • Open in EPA2 circuit

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 7. P2138
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

Engine switch on (IG)


  • Accelerator pedal fully released for 3 seconds

  • Accelerator pedal depressed partway for 3 seconds

  • Accelerator pedal fully depressed for 3 seconds

Conditions (a) or (b) continue for 2.0 seconds:

(1 trip detection logic)

(a) The difference between VPA and VPA2 is less than 0.02 V.

(b) VPA is below 0.4 V and VPA2 is below 1.2 V.

  • VPA and VPA2 circuits are short-circuited

  • Accelerator pedal position sensor

  • Accelerator pedal assembly

  • Accelerator pedal rod (arm) deformed

  • ECM
Table 8. Related Data List
DTC No. Data List

P2120

P2122

P2123

P2125

P2127

P2128

P2138

  • Accel Position

  • Accel Sens. No.1 Volt %

  • Accel Sens. No.2 Volt %
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WIRING DIAGRAM

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INSPECTION PROCEDURE

Note:

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

  • After replacing the fuel supply pump assembly, the ECM needs initialization (Click here).

  • After replacing an injector assembly, the ECM needs registration (Click here).

Tip:

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.

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PROCEDURE


  1. Click here

    READ VALUE USING GTS (ACCELERATOR PEDAL POSITION)


    1. A015CLQE03

      Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

    3. Enter the following menus: Engine and ECT / Data List / Accel Sens. No.1 Volt % and Accel Sens. No.2 Volt %.

    4. Read the values.

      Standard
      Accelerator Pedal Accel Sens. No.1 Volt % Accel Sens. No.2 Volt %
      Released 10 to 22% 24 to 40%
      Depressed 52 to 90% 68 to 99%
      Table 9. Text in Illustration
      *1 Accelerator Pedal Assembly
      *a Depressed
      *b Released
      Table 10. Result
      Result Proceed to
      NG A
      OK B

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


    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
      Table 11. for LHD
      Tester Connection Condition Specified Condition
      A31-1 (VCP2) - A38-56 (VCP2) Always Below 1 Ω
      A31-2 (EPA2) - A38-58 (EPA2) Always Below 1 Ω
      A31-3 (VPA2) - A38-54 (VPA2) Always Below 1 Ω
      A31-4 (VCPA) - A38-55 (VCPA) Always Below 1 Ω
      A31-5 (EPA) - A38-57 (EPA) Always Below 1 Ω
      A31-6 (VPA) - A38-53 (VPA) Always Below 1 Ω
      A31-1 (VCP2) or A38-56 (VCP2) - Body ground Always 10 kΩ or higher
      A31-2 (EPA2) or A38-58 (EPA2) - Body ground Always 10 kΩ or higher
      A31-3 (VPA2) or A38-54 (VPA2) - Body ground Always 10 kΩ or higher
      A31-4 (VCPA) or A38-55 (VCPA) - Body ground Always 10 kΩ or higher
      A31-5 (EPA) or A38-57 (EPA) - Body ground Always 10 kΩ or higher
      A31-6 (VPA) or A38-53 (VPA) - Body ground Always 10 kΩ or higher
      Standard Resistance
      Table 12. for RHD
      Tester Connection Condition Specified Condition
      A31-1 (VCP2) - A52-56 (VCP2) Always Below 1 Ω
      A31-2 (EPA2) - A52-58 (EPA2) Always Below 1 Ω
      A31-3 (VPA2) - A52-54 (VPA2) Always Below 1 Ω
      A31-4 (VCPA) - A52-55 (VCPA) Always Below 1 Ω
      A31-5 (EPA) - A52-57 (EPA) Always Below 1 Ω
      A31-6 (VPA) - A52-53 (VPA) Always Below 1 Ω
      A31-1 (VCP2) or A52-56 (VCP2) - Body ground Always 10 kΩ or higher
      A31-2 (EPA2) or A52-58 (EPA2) - Body ground Always 10 kΩ or higher
      A31-3 (VPA2) or A52-54 (VPA2) - Body ground Always 10 kΩ or higher
      A31-4 (VCPA) or A52-55 (VCPA) - Body ground Always 10 kΩ or higher
      A31-5 (EPA) or A52-57 (EPA) - Body ground Always 10 kΩ or higher
      A31-6 (VPA) or A52-53 (VPA) - Body ground Always 10 kΩ or higher

    4. Reconnect the accelerator pedal position sensor connector.

    5. Reconnect the ECM connector.


  3. Click here

    INSPECT ECM TERMINAL VOLTAGE (VCPA AND VCP2 TERMINALS)


    1. A015BGBE32

      Disconnect the accelerator pedal position sensor connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A31-4 (VCPA) - A31-5 (EPA) Engine switch on (IG) 4.5 to 5.5 V
      A31-1 (VCP2) - A31-2 (EPA2) Engine switch on (IG) 4.5 to 5.5 V
      Table 13. Text in Illustration
      *a

      Front view of wire harness connector

      (to Accelerator Pedal Position Sensor)

    3. Reconnect the accelerator pedal position sensor connector.


  4. Click here

    REPLACE ACCELERATOR PEDAL ROD ASSEMBLY


    1. Replace the accelerator pedal rod assembly (Click here).


  5. Click here

    REPLACE ECM


    1. Replace the ECM (Click here).


  6. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


  7. Click here

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs (Click here).

    3. Turn the engine switch off and leave the vehicle for 30 seconds.

    4. Turn the engine switch on (IG).

    5. Fully release the accelerator pedal for 3 seconds or more, then depress it partway for 3 seconds or more, and then fully depress it for 3 seconds or more.

    6. Confirm that the DTC is not output again.


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    END