SFI SYSTEM, Diagnostic DTC:P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135

DTC Code DTC Name
P0120 Throttle / Pedal Position Sensor / Switch "A" Circuit
P0121 Throttle Pedal Position Sensor / Switch "A" Circuit Range / Performance
P0122 Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input
P0123 Throttle / Pedal Position Sensor / Switch "A" Circuit High Input
P0220 Throttle / Pedal Position Sensor / Switch "B" Circuit
P0222 Throttle / Pedal Position Sensor / Switch "B" Circuit Low Input
P0223 Throttle / Pedal Position Sensor / Switch "B" Circuit High Input
P2135 Throttle / Pedal Position Sensor / Switch "A" / "B" Voltage Correlation

DESCRIPTION

The throttle position sensor is mounted on the throttle body with motor assembly and detects the opening angle of the throttle valve. This sensor is a non-contact type. It uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions, such as at high speeds as well as very low speeds.

The throttle position sensor has 2 sensor circuits, each of which transmits a signal, VTA1 and VTA2. VTA1 is used to detect the throttle valve angle and VTA2 is used to detect malfunctions in VTA1. The sensor signal voltages vary between 0 V and 5 V in proportion to the throttle valve opening angle, and are transmitted to the VTA terminals of the ECM.

As the valve closes, the sensor output voltage decreases and as the valve opens, the sensor output voltage increases. The ECM calculates the throttle valve opening angle according to these signals and controls the throttle actuator in response to driver inputs. These signals are also used in calculations such as air fuel ratio correction, power increase correction and fuel-cut control.

A01DOS9E85
DTC Code DTC Detection Condition Trouble Area
P0120 The output voltage of VTA1 quickly fluctuates beyond the lower and upper malfunction thresholds for 2 seconds when the accelerator pedal is depressed (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • ECM

P0121 The difference between the VTA1 and VTA2 voltages is less than 0.8 V, or more than 1.6 V for 2 seconds (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • Throttle position sensor circuit

  • ECM

P0122 The output voltage of VTA1 is 0.2 V or less for 2 seconds when the accelerator pedal is depressed (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • Short in VTA1 circuit

  • Open in VC circuit

  • ECM

P0123 The output voltage of VTA1 is 4.535 V or higher for 2 seconds when the accelerator pedal is depressed (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • Open in VTA1 circuit

  • Open in E2 circuit

  • Short between VC and VTA1 circuits

  • ECM

P0220 The output voltage of VTA2 quickly fluctuates beyond the lower and upper malfunction thresholds for 2 seconds when the accelerator pedal is depressed (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • ECM

P0222 The output voltage of VTA2 is 1.75 V or less for 2 seconds when the accelerator pedal is depressed (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • Short in VTA2 circuit

  • Open in VC circuit

  • ECM

P0223 The output voltage of VTA2 is 4.8 V or higher, and VTA1 is between 0.2 V and 2.02 V for 2 seconds when the accelerator pedal is depressed (1 trip detection logic).
  • Throttle position sensor (built into throttle body with motor assembly)

  • Open in VTA2 circuit

  • Open in E2 circuit

  • Short between VC and VTA2 circuits

  • ECM

P2135

Either condition (a) or (b) is met (1 trip detection logic):

(a) The difference between the output voltages of VTA1 and VTA2 is 0.02 V or less for 0.5 seconds or more.

(b) The output voltage of VTA1 is 0.2 V or less and VTA2 is 1.75 V or less for 0.4 seconds or more.


  • Short between VTA1 and VTA2 circuits

  • Throttle position sensor (built into throttle body with motor assembly)

  • ECM

Tech Tips


  • When any of these DTCs are output, check the throttle valve opening angle by entering the following menus: Powertrain / Engine and ECT / Data List / ETCS / Throttle Position No. 1 and Throttle Position No. 2.


  • Throttle Position No. 1 is the VTA1 signal, and Throttle Position No. 2 is the VTA2 signal.

    Reference (Normal Condition)
    Tester Display Accelerator Pedal Fully Released Accelerator Pedal Fully Depressed
    Throttle Position No. 1 0.5 to 1.1 V 3.2 to 4.8 V
    Throttle Position No. 2 2.1 to 3.1 V 4.6 to 4.98 V

MONITOR DESCRIPTION

The ECM uses the throttle position sensor to monitor the throttle valve opening angle. There are several checks that the ECM performs to confirm that the throttle position sensor is operating properly.


If the malfunction is not repaired successfully, a DTC is stored 10 seconds after the engine is next started.


FAIL-SAFE

When any of these DTCs as well as other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions are stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the throttle valve is returned to a 7° throttle angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing in accordance with the accelerator pedal opening angle to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.

The ECM continues operating fail-safe mode until a pass condition is detected, and the ignition switch is then turned off.

WIRING DIAGRAM

A01DRQKE03

INSPECTION PROCEDURE

Tech Tips


  • These DTCs relate to the throttle 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. READ VALUE USING INTELLIGENT TESTER (THROTTLE POSITION SENSOR)


    1. Connect the intelligent tester to the DLC3.

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

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / ETCS / Throttle Position No. 1 and Throttle Position No. 2.

    4. Check the values displayed on the tester.

      Result
      Throttle Position No. 1 Throttle Position No. 2 Throttle Position No. 1 Throttle Position No. 2 Trouble Area Proceed to
      When Accelerator Pedal Released When Accelerator Pedal Depressed
      0 to 0.2 V 0 to 0.2 V 0 to 0.2 V 0 to 0.2 V VC circuit open A
      4.5 to 4.98 V 4.5 to 4.98 V 4.5 to 4.98 V 4.5 to 4.98 V E2 circuit open

      0 to 0.2 V,

      or 4.5 to 4.98 V

      2.1 to 3.1 V

      (Fail-safe)

      0 to 0.2 V,

      or 4.5 to 4.98 V

      2.1 to 3.1 V

      (Fail-safe)

      VTA1 circuit open or ground short

      0.6 to 1.4 V

      (Fail-safe)

      0 to 0.2 V,

      or 4.5 to 4.98 V

      0.6 to 1.4 V

      (Fail-safe)

      0 to 0.2 V,

      or 4.5 to 4.98 V

      VTA2 circuit open or ground short
      0.5 to 1.1 V 2.1 to 3.1 V

      3.2 to 4.8 V

      (Not fail-safe)

      4.6 to 4.98 V

      (Not fail-safe)

      Throttle position sensor circuit normal B

      Tech Tips


      • DTC P0121 is stored when the voltages output from VTA1 and VTA2 are not consistent with the characteristics of the sensors. Therefore, check the freeze frame data when this DTC is output. Use the following formula to confirm relative fluctuations in voltage.


        • Characteristics of sensor output:
        • VTA2 x 0.8 is approximately equal to VTA1 + 1.11 V

        • VTA1: Throttle Position No. 1

        • VTA2: Throttle Position No. 2

      • If DTC P0121 is output, proceed to "CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)".


    B
    A
  2. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)


    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C13-5 (VC) - C36-13 (VCTA) Always Below 1 Ω
      C13-6 (VTA) - C36-15 (VTA1) Always Below 1 Ω
      C13-4 (VTA2) - C36-16 (VTA2) Always Below 1 Ω
      C13-3 (E2) - C36-14 (ETA) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C13-5 (VC) or C36-13 (VCTA) - Body ground Always 10 kΩ or higher
      C13-6 (VTA) or C36-15 (VTA1) - Body ground Always 10 kΩ or higher
      C13-4 (VTA2) or C36-16 (VTA2) - Body ground Always 10 kΩ or higher
    4. Reconnect the throttle body with motor assembly connector.

    5. Reconnect the ECM connector.


    NG
    OK
  3. INSPECT ECM (VC VOLTAGE)

    A01DSJFE12
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Throttle Body with Motor Assembly)


    1. Disconnect the throttle body with motor assembly connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C13-5 (VC) - C13-3 (E2) Ignition switch ON 4.5 to 5.5 V
    3. Reconnect the throttle body with motor assembly connector.


    NG
    OK
  4. REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY


    1. Replace the throttle body with motor assembly Click here.


    NEXT
  5. CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)


    1. Connect the intelligent tester to the DLC3.

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

    3. Clear the DTCs Click here.

    4. Start the engine.

    5. Allow the engine to idle for 15 seconds or more.

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

    7. Read the DTCs.

      Result
      Result Proceed to
      P0120, P0121, P0122, P0123, P0220, P0222, P0223 and/or P2135 A
      No output B

    B
    A