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 No. DTC Detection Condition Trouble Area
P2121

Difference between VPA and VPA2 less than 0.4 V, or more than 1.2 V for 0.5 seconds

(1-trip detection logic)

  • Accelerator pedal position sensor (accelerator pedal assembly)


  • ECM

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

Refer to DTC P2120 Click here.

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using an 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2121)


    1. 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 / DTC.

    5. Read DTCs.

      Result
      Result Proceed to
      P2121 A
      P2121 and other DTCs 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 NO. 1 AND ACCELERATOR POSITION NO. 2)


    1. A0118O3E18

      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 / Accelerator Position No. 1 and Accelerator Position No. 2.

    5. Read the values.

      Standard Voltage
      Accelerator Pedal Operation Accelerator Position No. 1 Accelerator Position No. 2
      Released 0.5 to 1.1 V 1.2 to 2.0 V
      Depressed 2.5 to 4.5 V 3.4 to 5.0 V
      Result
      Result Proceed to
      Outside standard range A
      Within standard range B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  3. REPLACE ACCELERATOR PEDAL ASSEMBLY


    1. Replace the accelerator pedal assembly Click here.


    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)


    1. 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 / DTC / Clear.

    5. Clear DTCs.

    6. Start the engine.

    7. Allow the engine to idle for 15 seconds.

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

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

    10. Read DTCs.

      Result
      Result Proceed to
      P2121 A
      No output B

    B

    END

    A

    REPLACE ECM Click here