SFI SYSTEM(w/o EGR System), Diagnostic DTC:P2121

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

DESCRIPTION

Tip:

Refer to DTC P2120 (Click here).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

P2121

Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

Difference between VPA and VPA2 is less than 0.4 V, or more than 1.2 V for 0.5 seconds (1 trip detection logic).

  • Accelerator Pedal Position sensor assembly

  • ECM

Comes on

DTC stored

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 sensor is malfunctioning. The ECM turns on the MIL and stores the DTC.

CONFIRMATION DRIVING PATTERN

A199317E24

  1. Connect the intelligent tester to the DLC3.

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

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

  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. Fully depress and release the accelerator pedal [B].

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

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

  9. Read the pending DTCs.

    Tip:

    • 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

    UNKNOWN

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    Tip:

    • 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 UNKNOWN, perform steps [B] through [C] again.

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).

CAUTION / NOTICE / HINT

Tip:

  • This DTC relates to the accelerator pedal position 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 FOR 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.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      P2121 is output

      A

      P2121 and other DTCs are output

      B
      Tip:

      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 PEDAL POSITION SENSOR)

    1. A208621C01

      *a

      Depressed

      *b

      Released

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

      Powertrain > Engine and ECT > Data List

      Tester Display

      Accel Sensor Out No.1

      Accel Sensor Out No.2

    5. Read the value displayed on the tester.

      Standard Voltage

      Accelerator Pedal Operation

      Accel Sensor Out No. 1

      Accel Sensor Out No. 2

      Difference between Accel Sensor Out No. 1 and Accel Sensor Out No. 2

      Released

      0.5 to 1.1 V

      1.2 to 2.0 V

      More than 0.02 V

      Depressed

      2.6 to 4.5 V

      3.4 to 4.7 V

      Result

      Result

      OK

      NG
    OK

    CHECK FOR INTERMITTENT PROBLEMS

    Click here

    NG

  3. REPLACE ACCELERATOR PEDAL POSITION SENSOR ASSEMBLY

    1. Replace the accelerator pedal position sensor assembly.

      Click here

      Result

      Result

      NEXT
    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)

    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

      Powertrain > Engine and ECT > Clear DTCs

    5. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    6. Read DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      P2121 is output

      A

      No DTC is output

      B
    A

    REPLACE ECM

    Click here

    B

    END