SFI SYSTEM, Diagnostic DTC:P2121

DTC Code DTC Name
P2121 Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

DESCRIPTION

Tech Tips

Refer to DTC P2120 Click here.

DTC Code DTC Detection Condition Trouble Area
P2121

Either conditions (1) or (2) met for 0.5 seconds (1 trip detection logic):


  • (1) Difference between VPA and VPA2 is less than 0.4 V, or more than 1.2 V. (learned value of accelerator off position)

  • (2) Difference between VPA and VPA2 is greater than or equal to the specified value.

  • Accelerator Pedal Position (APP) sensor

  • ECM

MONITOR DESCRIPTION

When the difference between the output voltages of VPA and VPA2 deviates from the standard, the ECM determines that the Accelerator Pedal Position (APP) sensor is malfunctioning. The ECM turns on the MIL and the DTC is stored.

FAIL-SAFE

When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 is stored, the ECM enters fail-safe mode. If either of the 2 sensor circuits malfunctions, the ECM uses the remaining circuit to calculate the accelerator pedal position to allow the vehicle to continue driving. If both of the circuits malfunction, the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the engine idles.

Fail-safe mode continues until a pass condition is detected, and the engine switch is turned off.

CONFIRMATION DRIVING PATTERN

B001AXOE57

  1. Connect the intelligent tester to the DLC3.

  2. Turn the engine switch on (IG) and turn the tester on.

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

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

  5. Turn the engine switch on (IG) and turn the tester on [A].

  6. Wait for 5 seconds after turning the engine switch on (IG).

  7. Operate the accelerator pedal in accordance with the following procedure [B].


    1. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sens. No. 1 Volt %, and Accel Sens. No. 2 Volt %.

    2. Slowly depress the accelerator pedal until Accel Sens. No. 1 Volt % is approximately 30% and Accel Sens. No. 2 Volt % is approximately 46%, then slowly release the accelerator pedal.

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

  9. Read the 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: P2121.

  12. Check the DTC judgment result.

    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
    N/A

    • 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 N/A, perform steps [B] and [C] again.

WIRING DIAGRAM

Refer to DTC P2120 Click here.

CAUTION / NOTICE / HINT

Tech Tips


  • This DTC relates to the Accelerator Pedal Position (APP) sensor.

  • 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2121)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

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

    5. Read DTCs.

      Result
      Result Proceed to
      P2121 is output A
      P2121 and other DTCs are output B

      Tech Tips

      If any DTCs other than P2121 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

    B0018C7E68
    *1 Depressed
    *2 Released

    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester on.

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

    4. Read the values displayed on the tester.

      Standard Voltage
      Accelerator Pedal Operations Accel Sensor Out No. 1 Accel Sensor Out No. 2
      Released 0.5 to 1.1 V 1.2 to 2.0 V
      Depressed 2.6 to 4.5 V 3.4 to 4.7 V

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

  3. REPLACE ACCELERATOR PEDAL


    1. Replace the accelerator pedal assembly Click here.


    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester on.

    3. Clear DTCs Click here.

    4. Start the engine.

    5. Refer to the confirmation driving pattern.

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

    7. Read DTCs.

      Result
      Result Proceed to
      P2121 is output A
      No DTC is output B

    A

    REPLACE ECM Click here

    B

    SYSTEM OK