SFI SYSTEM, 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 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.

Tip:

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

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

A257314E05

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P2122

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

VPA is 0.7 V or less for 0.14 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

Comes on

DTC stored

P2123

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

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

Comes on

DTC stored

P2127

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

VPA2 is 1.5 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

Comes on

DTC stored

P2128

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

VPA2 is 4.7 V or more for 0.14 seconds or more (1 trip detection logic).

  • Accelerator pedal sensor assembly

  • Open in EPA2 circuit

  • Short in VPA2 circuit

  • ECM

Comes on

DTC stored

WIRING DIAGRAM

A254543E03

CONFIRMATION DRIVING PATTERN

These DTCs are detected when the ignition switch is ON or engine running.

CAUTION / NOTICE / HINT

Note:

  • After replacing the ECM, perform idle learning.

    Click here

  • If any DTCs related to the crankshaft position sensor, throttle position sensor, accelerator pedal sensor assembly, manifold absolute pressure sensor and camshaft position sensor are output simultaneously, inspect the VC circuit of each component.

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, 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

      A34-53 (VCPA) - A22-4 (VCPA)

      Always

      Below 1 Ω

      A34-51 (VPA) - A22-6 (VPA)

      Always

      Below 1 Ω

      A34-52 (EPA) - A22-5 (EPA)

      Always

      Below 1 Ω

      A34-56 (VCP2) - A22-1 (VCP2)

      Always

      Below 1 Ω

      A34-54 (VPA2) - A22-3 (VPA2)

      Always

      Below 1 Ω

      A34-55 (EPA2) - A22-2 (EPA2)

      Always

      Below 1 Ω

      A34-53 (VCPA) or A22-4 (VCPA) - Body ground

      Always

      10 kΩ or higher

      A34-51 (VPA) or A22-6 (VPA) - Body ground

      Always

      10 kΩ or higher

      A34-52 (EPA) or A22-5 (EPA) - Body ground

      Always

      10 kΩ or higher

      A34-56 (VCP2) or A22-1 (VCP2) - Body ground

      Always

      10 kΩ or higher

      A34-54 (VPA2) or A22-3 (VPA2) - Body ground

      Always

      10 kΩ or higher

      A34-55 (EPA2) or A22-2 (EPA2) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ACCELERATOR PEDAL SENSOR ASSEMBLY)

    A254580C28

    *a

    Front view of wire harness connector

    (to Accelerator Pedal Sensor Assembly)

    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

      Condition

      Specified Condition

      A22-1 (VCP2) - A22-2 (EPA2)

      Ignition switch ON

      4.5 to 5.5 V

      A22-4 (VCPA) - A22-5 (EPA)

      Ignition switch ON

      4.5 to 5.5 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

    Click here

    NG

    REPLACE ECM

    Click here