ECD SYSTEM(w/o Glow Plug Controller), Diagnostic DTC:P2122,P2123,P2127 and P2128

DTC Code DTC Name
P2122 Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input
P2123 Throttle / Pedal Position Sensor / Switch "D" Circuit High Input
P2127 Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input
P2128 Throttle / Pedal Position Sensor / Switch "E" Circuit High Input

DESCRIPTION

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. The accelerator pedal position sensor has 2 sensors to detect the accelerator position and malfunctions 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 0.5 V and 5.5 V in proportion to the opening angle of the accelerator pedal. The VPA is a signal which indicates the actual accelerator pedal opening angle and is used for engine control, and the VPA2 is a signal which indicates the information about the opening angle and is used for detecting malfunctions. The ECM judges the current opening angle of the accelerator pedal using signals from terminals VPA and VPA2, and the ECM controls the injection volume based on these signals.

A261002E03

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P2122

Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input

VPA is less than 0.2 V for 0.5 seconds or more when accelerator pedal is depressed.

(1 trip detection logic)

  • Open or short in accelerator pedal sensor assembly circuit

  • Accelerator pedal position sensor

  • ECM

Comes on

DTC stored

P2123

Throttle / Pedal Position Sensor / Switch "D" Circuit High Input

VPA is higher than 4.8 V for 0.5 seconds or more.

(1 trip detection logic)

  • Open or short in accelerator pedal sensor assembly circuit

  • Accelerator pedal position sensor

  • ECM

Comes on

DTC stored

P2127

Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input

VPA2 is less than 0.5 V for 0.5 seconds or more when accelerator pedal is depressed.

(1 trip detection logic)

  • Open or short in accelerator pedal sensor assembly circuit

  • Accelerator pedal position sensor

  • ECM

Comes on

DTC stored

P2128

Throttle / Pedal Position Sensor / Switch "E" Circuit High Input

VPA2 is higher than 4.8 V for 0.5 seconds or more.

(1 trip detection logic)

  • Open or short in accelerator pedal sensor assembly circuit

  • Accelerator pedal position sensor

  • ECM

Comes on

DTC stored
Table 1. DTC Detection Drive Pattern

DTC No.

DTC Detection Drive Pattern

P2122

Ignition switch ON

P2123

P2127

P2128
Table 2. Related Data List

DTC No.

Data List

P2122

P2123

P2127

P2128

  • Accel Position

  • Accel Sens. No. 1 Volt %

  • Accel Sens. No. 2 Volt %

  • Accel Sensor Out No.1

  • Accel Sensor Out No.2
Tip:

  • When DTC P2122, P2123, P2127 and/or P2128 are stored, as a fail-safe operation the ECM limits engine power, such as by estimating the accelerator pedal position as 0 %.

  • When DTC P2122, P2123, P2127 and/or P2128 are stored, check the accelerator pedal position sensor output by entering the following menus on the GTS: Powertrain / Engine and ECT / Data List / Accel Position.

Table 3. Reference

Accelerator Pedal Position

(Fully Closed)

Accelerator Pedal Position

(Fully Open)

Trouble Area

0%

0%

  • Open in VCPA or VCP2 circuit

  • Open or short in VPA or VPA2 circuit

Approximately 100%

Approximately 100%

  • Open in EPA or EPA2 circuit

WIRING DIAGRAM

A293514E01

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. READ VALUE USING GTS (ACCEL SENSOR OUT NO.1 AND NO.2)

    1. C129061C01

      *1

      Accelerator Pedal

      *a

      Fully depressed

      *b

      Fully 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 Sensor Out No.1 and Accel Sensor Out No.2.

      Powertrain > Engine and ECT > Data List

      Tester Display

      Accel Sensor Out No.1

      Accel Sensor Out No.2

    4. Read the value when fully depressing and fully releasing the accelerator pedal.

      Standard Voltage

      GTS Display

      Condition

      Specified Condition

      Accel Sensor Out No.1

      Fully depressed

      2.6 to 4.5 V

      Fully released

      0.5 to 1.1 V

      Accel Sensor Out No.2

      Fully depressed

      3.4 to 4.75 V

      Fully released

      1.2 to 2.0 V

    Result

    Proceed to

    OK

    NG
    NG

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

    OK

  2. 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. Fully close the accelerator pedal for 3 seconds, and then hold it partway open for 3 seconds, then fully open it for 3 seconds.

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

    8. Confirm that the DTC is not output again.

      Powertrain > Engine and ECT > Trouble Codes

    Result

    Proceed to

    NEXT
    NEXT

    END

  3. 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

      A3-1 (VCP2) - A101-53 (VCP2)

      Always

      Below 1 Ω

      A3-2 (EPA2) - A101-54 (EPA2)

      Always

      Below 1 Ω

      A3-3 (VPA2) - A101-52 (VPA2)

      Always

      Below 1 Ω

      A3-4 (VCPA) - A101-56 (VCPA)

      Always

      Below 1 Ω

      A3-5 (EPA) - A101-57 (EPA)

      Always

      Below 1 Ω

      A3-6 (VPA) - A101-55 (VPA)

      Always

      Below 1 Ω

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

      Always

      10 kΩ or higher

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

      Always

      10 kΩ or higher

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

      Always

      10 kΩ or higher

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

      Always

      10 kΩ or higher

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

      Always

      10 kΩ or higher

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

    1. A254580C01

      *a

      Front view of wire harness connector

      (to Accelerator Pedal Sensor Assembly)

      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

  5. REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

    1. Replace the accelerator pedal sensor assembly.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  6. CHECK WHETHER DTC OUTPUT RECURS

    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. Fully close the accelerator pedal for 3 seconds, and then hold it partway open for 3 seconds, then fully open it for 3 seconds.

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

    8. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P2122, P2123, P2127 and/or P2128 is output

      A

      DTC is not output

      B
    B

    END

    A

  7. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here