SFI 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.

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 fail-safe mode. In fail-safe 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 position of 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 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).

CAUTION / NOTICE / HINT

Tip:

Read freeze frame data using the GTS. 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 the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    4. Read the DTCs.

      Table 1. Result

      Result

      Proceed to

      DTC P2121 is output

      A

      DTC P2121 and other DTCs are output

      B
      Tip:

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

    GO TO DTC CHART

    (Click here)

  2. READ VALUE USING GTS (ACCELERATOR PEDAL POSITION)

    1. A208621E01

      Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

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

    4. Read the values displayed on the GTS.

      Standard Voltage

      Accelerator Pedal Operation

      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 4.75 V

    CHECK FOR INTERMITTENT PROBLEMS

    (Click here)

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

    1. Replace the accelerator pedal assembly (Click here).

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs (Click here).

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

    5. Wait for 5 seconds after turning the ignition switch to ON.

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

    7. 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 / Trouble Codes.

    9. Read the DTCs.

      Table 2. Result

      Result

      Proceed to

      DTC P2121 is output

      A

      DTC is not output

      B

    REPLACE ECM

    (Click here)

    SYSTEM OK