SFI 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

The accelerator pedal position sensor is mounted on the accelerator pedal sensor assembly 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 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 V and 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 throttle motor based on these signals.

Tech Tips


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

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

A01VJ1HE07
DTC No. DTC Detection Condition Trouble Area
P2122

VPA is 0.7 V or less for 0.5 seconds or more when VPA2 output indicates accelerator pedal is depressed

(1 trip detection logic)

  • Accelerator pedal sensor assembly

  • Open in VCPA circuit

  • VPA circuit open or ground short

  • ECM
P2123

VPA is 3.9 V or more for 0.14 seconds or more

(1 trip detection logic)

  • Accelerator pedal sensor assembly

  • Open in EPA circuit

  • Short in VCPA circuit

  • ECM
P2127

VPA2 is 0.68 V or less for 0.14 seconds or more when VPA output indicates accelerator pedal is depressed

(1 trip detection logic)

  • Accelerator pedal sensor assembly

  • Open in VCP2 circuit

  • VPA2 circuit open or ground short

  • ECM
P2128

VPA2 is 3.9 V or more for 0.14 seconds or more

(1 trip detection logic)

  • Accelerator pedal sensor assembly

  • Open in EPA2 circuit

  • Short in VCPA2 circuit

  • ECM

Tech Tips

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

WIRING DIAGRAM

A01VE4NE05
*a Accelerator Pedal Sensor Assembly

CAUTION / NOTICE / HINT

Note

Perform electronic throttle learning after replacing the ECM Click here.

Tech Tips

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (ECM - ACCELERATOR PEDAL SENSOR ASSEMBLY)


    1. Disconnect the ECM connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A71-11 (VCPA) - A36-4 (VCPA) Always Below 1 Ω
      A71-9 (VPA) - A36-6 (VPA) Always Below 1 Ω
      A71-10 (EPA) - A36-5 (EPA) Always Below 1 Ω
      A71-19 (VCP2) - A36-1 (VCP2) Always Below 1 Ω
      A71-17 (VPA2) - A36-3 (VPA2) Always Below 1 Ω
      A71-18 (EPA2) - A36-2 (EPA2) Always Below 1 Ω
      A71-11 (VCPA) or A36-4 (VCPA) - Body ground Always 10 kΩ or higher
      A71-9 (VPA) or A36-6 (VPA) - Body ground Always 10 kΩ or higher
      A71-10 (EPA) or A36-5 (EPA) - Body ground Always 10 kΩ or higher
      A71-19 (VCP2) or A36-1 (VCP2) - Body ground Always 10 kΩ or higher
      A71-17 (VPA2) or A36-3 (VPA2) - Body ground Always 10 kΩ or higher
      A71-18 (EPA2) or A36-2 (EPA2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (ACCELERATOR PEDAL SENSOR ASSEMBLY)

    A01VLTTE01

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

    OK

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    NG

    REPLACE ECM Click here