SFI SYSTEM, Diagnostic DTC:P2120, P2122, P2123, P2125, P2127, P2128, P2138

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

DESCRIPTION

Tech Tips


  • These DTCs relate to the Accelerator Pedal Position (APP) sensor.

  • This ETCS (Electronic Throttle Control System) does not use a throttle cable.

The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type. It uses Hall-effect elements in order to yield accurate signals, even in extreme driving conditions, such as at high speeds as well as very low speeds. The voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0 V and 5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the APP sensor itself.

The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

A005MINE89
DTC No. DTC Detection Condition Trouble Area
P2120

VPA fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more

(1 trip detection logic)

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • ECM
P2122

VPA 0.4 V or less for 0.5 seconds or more when accelerator pedal depressed

(1 trip detection logic)

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • Open in VCPA circuit

  • Open or ground short in VPA circuit

  • ECM
P2123

VPA 4.8 V or more for 2.0 seconds or more

(1 trip detection logic)

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • Open in EPA circuit

  • ECM
P2125

VPA2 fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more

(1 trip detection logic)

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • ECM
P2127

VPA2 1.2 V or less for 0.5 seconds or more when accelerator pedal depressed

(1 trip detection logic)

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • Open in VCP2 circuit

  • Open or ground short in VPA2 circuit

  • ECM
P2128

Following conditions (a) and (b) met for 2.0 seconds or more

(1 trip detection logic):

(a) VPA2 4.8 V or more

(b) VPA between 0.4 V and 3.45 V

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • Open in EPA2 circuit

  • ECM
P2138

Either of following conditions (a) or (b) met for 2.0 seconds or more

(1 trip detection logic):

(a) Difference between VPA and VPA2 0.02 V or less

(b) VPA 0.4 V or less and VPA2 1.2 V or less

  • Short between VPA and VPA2 circuits

  • Accelerator pedal position sensor (accelerator pedal assembly)

  • ECM

Tech Tips

When any of these DTCs are set, check the accelerator pedal position sensor voltage by entering the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

Trouble Area

Accel Sensor Out No. 1

When AP Released

Accel Sensor Out No. 2

When AP Released

Accel Sensor Out No. 1

When AP Depressed

Accel Sensor Out No. 2

When AP Depressed
VCP circuit open 0 to 0.2 V 0 to 0.2 V 0 to 0.2 V 0 to 0.2 V
Open or ground short in VPA circuit 0 to 0.2 V 1.2 to 2.0 V 0 to 0.2 V 3.4 to 5.0 V
Open or ground short in VPA2 circuit 0.5 to 1.1 V 0 to 0.2 V 2.6 to 4.5 V 0 to 0.2 V
EPA circuit open 4.5 to 5.0 V 4.5 to 5.0 V 4.5 to 5.0 V 4.5 to 5.0 V
Normal condition 0.5 to 1.1 V 1.2 to 2.0 V 2.6 to 4.5 V 3.4 to 5.0 V

Tech Tips

AP denotes Accelerator Pedal.

MONITOR DESCRIPTION

When the output voltage of either VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the accelerator pedal position sensor. The ECM then illuminates the MIL and stores a DTC.

Example:

When the output voltage of VPA drops below 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is stored.

CONFIRMATION DRIVING PATTERN

A005IDBE01

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and turn the intelligent tester on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

  4. Turn the ignition switch off and wait for at least 30 seconds.

  5. Turn the ignition switch to ON and turn the intelligent tester on [A].

  6. Fully depress and release the accelerator pedal [B].

  7. Check that 5 seconds or more have elapsed since the ignition switch was turned to ON.

  8. Enter the following menus: Powertrain / Engine and ECT / DTC [C].

  9. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  11. Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.

  12. Check the DTC judgment result.

    Intelligent tester Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    UNKNOWN

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [C] again.

FAIL-SAFE

The APP sensor has two (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor circuits and switches to fail-safe mode. In fail-safe mode, the functioning circuit is used to calculate the accelerator pedal opening angle to allow the vehicle to continue driving. If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal as being fully closed. In this case, the throttle valve remains closed as if the engine is idling. If a pass condition is detected and then the ignition switch is turned off, the fail-safe operation stops and the system returns to a normal condition.

WIRING DIAGRAM

A005J85E13
*a ACCELERATOR PEDAL POSITION SENSOR (ACCELERATOR PEDAL ASSEMBLY)

CAUTION / NOTICE / HINT

Tech Tips


  • These DTCs relate to the accelerator pedal position sensor.

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


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


    1. A005L1HE03
      Text in Illustration
      *a Accelerator Pedal
      *b Depressed
      *c Released

      Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

    5. Read the value.

      Standard Voltage
      Accelerator Pedal Operation Accel Sensor Out No. 1 Accel Sensor Out No. 2 Difference between Accel Sensor Out No. 1 and Accel Sensor Out No. 2
      Released 0.5 to 1.1 V 1.2 to 2.0 V More than 0.02 V
      Depressed 2.6 to 4.5 V 3.4 to 4.7 V

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

  2. 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 (Check for Open)
      Tester Connection Condition Specified Condition
      A36-6 (VPA) - A58-51 (VPA) Always Below 1 Ω
      A36-5 (EPA) - A58-52 (EPA) Always Below 1 Ω
      A36-4 (VCPA) - A58-53 (VCPA) Always Below 1 Ω
      A36-3 (VPA2) - A58-54 (VPA2) Always Below 1 Ω
      A36-2 (EPA2) - A58-55 (EPA2) Always Below 1 Ω
      A36-1 (VCP2) - A58-56 (VCP2) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A36-6 (VPA) or A58-51 (VPA) - Body ground Always 10 kΩ or higher
      A36-5 (EPA) or A58-52 (EPA) - Body ground Always 10 kΩ or higher
      A36-4 (VCPA) or A58-53 (VCPA) - Body ground Always 10 kΩ or higher
      A36-3 (VPA2) or A58-54 (VPA2) - Body ground Always 10 kΩ or higher
      A36-2 (EPA2) or A58-55 (EPA2) - Body ground Always 10 kΩ or higher
      A36-1 (VCP2) or A58-56 (VCP2) - Body ground Always 10 kΩ or higher

    4. Reconnect the accelerator pedal position sensor connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ECM (VCPA AND VCP2 VOLTAGE)


    1. A005HYKE01
      Text in Illustration
      *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 Switch Condition Specified Condition
      A36-4 (VCPA) - A36-5 (EPA) Ignition switch ON 4.5 to 5.5 V
      A36-1 (VCP2) - A36-2 (EPA2) Ignition switch ON 4.5 to 5.5 V

    4. Reconnect the accelerator pedal position sensor connector.


    NG

    REPLACE ECM Click here

    OK

  4. REPLACE ACCELERATOR PEDAL ASSEMBLY


    1. Replace the accelerator pedal assembly Click here.


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTC)


    1. Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Allow the engine to idle for 15 seconds or more.

    6. Fully depress and release the accelerator pedal several times quickly.

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

    8. Read DTCs.

      Result
      Result Proceed to
      DTC P2120, P2122, P2123, P2125, P2127, P2128, and/or P2138 are output A
      DTC is not output B

    A

    REPLACE ECM Click here

    B

    END