SFI SYSTEM (w/ Electronic Throttle Control System), Diagnostic DTC:P2122, P2123, P2127, 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

Tech Tips


  • 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 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 malfunctions. The ECM judges 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.

A0136ZLE01
DTC No.

DTC Detection Condition

(All of following are 1 trip detection logic)

 Trouble Area
P2122 VPA is 0.7 V or less for 0.5 sec. or more when VPA2 output indicate accelerator pedal is opened

  • Accelerator pedal position sensor

  • Open in VCPA circuit

  • VPA circuit open or ground short

  • Accelerator pedal

  • ECM
P2123

  • Condition (a) continues for 2.0 sec. or more:


    1. VPA is 4.8 V or more

  • Accelerator pedal position sensor

  • Open in EPA circuit

  • Short in VCPA circuit

  • Accelerator pedal

  • ECM
P2127 VPA2 is 0.65 V or less for 0.5 sec. or more when VPA output indicates accelerator pedal is opened

  • Accelerator pedal position sensor

  • Open in VCP2 circuit

  • VPA2 circuit open or ground short

  • Accelerator pedal

  • ECM
P2128 VPA2 is 4.03 V or more for 2.0 sec. or more

  • Accelerator pedal position sensor

  • Open in EPA2 circuit

  • Short in VCPA2 circuit

  • Accelerator pedal

  • ECM

Tech Tips

Detection for P2122, P2123, P2127 and P2128 are performed when the ignition switch ON position or engine running.

WIRING DIAGRAM

A0136QAE01

INSPECTION PROCEDURE

Note

After replace the ECM, perform electronic throttle learning Click here.

Tech Tips

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)


    1. A01389FE02

      Disconnect A23 accelerator pedal position sensor connector.

    2. Disconnect the B25 ECM connector.

    3. Measure the resistance between the accelerator pedal position sensor connector and ECM connector.

      Standard resistance (check for open)
      Tester Connection Specified Condition
      VCPA (B25-11) - VCPA A23-4) Below 1 Ω
      VPA (B25-78) - VCPA A23-6) Below 1 Ω
      EPA (B25-21) - EPA A23-5) Below 1 Ω
      VCP2 (B25-10) - VCP2 A23-1) Below 1 Ω
      VPA2 (B25-79) - VPA2 A23-3) Below 1 Ω
      EPA2 (B25-39) - EPA2 A23-2) Below 1 Ω
      Standard resistance (check for short)
      Tester Connection Specified Condition
      VCPA (B25-11) or VCPA A23-4) - Body ground 10 kΩ or higher
      VPA (B25-78) or VCPA A23-6) - Body ground 10 kΩ or higher
      EPA (B25-21) or EPA A23-5) - Body ground 10 kΩ or higher
      VCP2 (B25-10) or VCP2 A23-1) - Body ground 10 kΩ or higher
      VPA2 (B25-79) or VPA2 A23-3) - Body ground 10 kΩ or higher
      EPA2 (B25-39) or EPA2 A23-2) - Body ground 10 kΩ or higher

    4. Reconnect the accelerator pedal position sensor connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (ACCELERATOR PEDAL POSITION SENSOR CONNECTOR)


    1. A013722E01

      Disconnect the A23 accelerator pedal position sensor connector.

    2. Measure the voltage of the accelerator pedal position sensor connector.

      Tester Connection Specified Condition
      VCP2 - EPA2 4.5 to 5.0 V
      VCPA - EPA 4.5 to 5.0 V

    3. Reconnect the accelerator pedal position sensor connector.

    4. Clear the DTC Click here.


    NG

    REPLACE ECM

    OK

    REPLACE ACCELERATOR PEDAL ASSEMBLY