SFI SYSTEM, Diagnostic DTC:P2121

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

DESCRIPTION

Refer to DTC P2120 Click here.

DTC No. DTC Detection Condition Trouble Area
P2121

Either of following 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 sensor

  • ECM

FAIL-SAFE

The accelerator pedal position 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 limp mode. In limp mode, the functioning circuit is used to calculate the accelerator pedal position to allow the vehicle to continue driving. If both circuits malfunction, the ECM regards the accelerator pedal as being fully released. In this case, the throttle valve remains closed as if the engine is idling.

If a pass condition is detected and then the engine switch is turned off, the fail-safe operation stops and the system returns to normal.

WIRING DIAGRAM

Refer to DTC P2120 Click here.

INSPECTION PROCEDURE

Tech Tips


  • This DTC relates to the accelerator pedal position sensor.

  • 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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

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 / DTC.

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P2121 is output A
      DTC 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)

    A019LU2E02
    Text in Illustration
    *a Fully Depressed
    *b Fully Released

    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 / Data List / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

    5. Read the values displayed on the tester.

      Standard Voltage
      Accelerator Pedal Operation Accel Sensor Out No. 1 Accel Sensor Out No. 2
      Fully Released 0.5 to 1.1 V 1.2 to 2.0 V
      Fully Depressed 2.6 to 4.5 V 3.4 to 4.75 V

    NG

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR) Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

  3. REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR)


    1. Replace the accelerator pedal sensor assembly Click here.


    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Start the engine.

    6. Fully depress and release the accelerator pedal.

    7. Check that 20 seconds or more have elapsed since the engine switch was turned to on (IG).

    8. Enter the following menus: Powertrain / Engine / DTC.

    9. Read the DTCs.

      Result
      Result Proceed to
      DTC P2121 is output A
      DTC is not output B

    B

    END

    A

    REPLACE ECM Click here