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 Problem
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

Tech Tips

This electrical throttle control system does not use a throttle cable.

The throttle position sensor is mounted on the throttle with motor body assembly, and detects the opening angle of the throttle valve. This sensor is a non-contact type, and 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 two sensor circuits which each 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.

A017DH6E62
DTC No. DTC Detection Condition Trouble Area
P0120 Output voltage of VTA1 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds (1 trip detection logic)

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

  • ECM
P0121 Difference between VTA1 and VTA2 voltages less than 0.8 V, or more than 1.6 V for 2 seconds (1 trip detection logic) Throttle position sensor (built into throttle with motor body assembly)
P0122 Output voltage of VTA1 is 0.2 V or less for 2 seconds (1 trip detection logic)

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

  • Short in VTA1 circuit

  • Open in VCTA circuit

  • ECM
P0123 Output voltage of VTA1 is 4.535 V or more for 2 seconds (1 trip detection logic)

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

  • Open in VTA1 circuit

  • Open in ETA circuit

  • Short between VCTA and VTA1 circuits

  • ECM
P0220 Output voltage of VTA2 quickly fluctuates beyond lower and upper malfunction thresholds for 2 seconds (1 trip detection logic)

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

  • ECM
P0222 Output voltage of VTA2 is 1.75 V or less for 2 seconds (1 trip detection logic)

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

  • Short in VTA2 circuit

  • Open in VCTA circuit

  • ECM
P0223 Output voltage of VTA2 is 4.8 V or more, and VTA1 is between 0.2 V and 2.02 V, for 2 seconds (1 trip detection logic)

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

  • Open in VTA2 circuit

  • Open in ETA circuit

  • Short between VCTA and VTA2 circuits

  • ECM
P2135

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

(a) Difference between output voltages of VTA1 and VTA2 is 0.02 V or less for 0.5 seconds or more

(b) 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 with motor body assembly)

  • ECM

Tech Tips


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

  • Throttle Position No. 1 denotes the VTA1 signal (expressed in percentages), and Throttle Position No. 2 denotes the VTA2 signal (expressed in voltages).

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 5.0 V

FAIL-SAFE

When either of these DTCs, or other DTCs relating to 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 6° 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 position 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 in fail-safe mode until a pass condition is detected, and the ignition switch is then turned off.

WIRING DIAGRAM

A017D35E41

INSPECTION PROCEDURE

Tech Tips

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. READ VALUE USING INTELLIGENT TESTER (THROTTLE POSITION)


    1. Connect the intelligent tester to the DLC3.

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

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

    4. Check the values displayed on the tester.

      Result
      When accelerator pedal released When accelerator pedal fully depressed Trouble Area Proceed to
      Throttle Position No. 1 Throttle Position No. 2 Throttle Position No. 1 Throttle Position No. 2
      0 to 0.2 V 0 to 0.2 V 0 to 0.2 V 0 to 0.2 V VCTA circuit open A
      4.5 to 5.0 V 4.5 to 5.0 V 4.5 to 5.0 V 4.5 to 5.0 V ETA circuit open A
      0 to 0.2 V or 4.5 to 5.0 V

      2.1 to 3.1 V

      (Fail-safe)

      		 0 to 0.2 V or 4.5 to 5.0 V

      2.1 to 3.1 V

      (Fail-safe)

      		 VTA1 circuit open or ground short A

      0.6 to 1.4 V

      (Fail-safe)

      		 0 to 0.2, or 4.5 to 5.0 V

      0.6 to 1.4 V

      (Fail-safe)

      		 0 to 0.2, or 4.5 to 5.0 V VTA2 circuit open or ground short A
      0.5 to 1.1 V 2.1 to 3.1 V

      3.2 to 4.8 V

      (Not fail-safe)

      4.6 to 5.0 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.

        Characteristic 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 the "CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)".


    B

    CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS) Click here

    A

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


    1. Disconnect the throttle with motor body 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
      B27-5 (VC) - B48-13 (VCTA) Always Below 1 Ω
      B27-6 (VTA) - B48-15 (VTA1) Always Below 1 Ω
      B27-4 (VTA2) - B48-16 (VTA2) Always Below 1 Ω
      B27-3 (E2) - B48-14 (ETA) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      B27-5 (VC) or B48-13 (VCTA) - Body ground Always 10 kΩ or higher
      B27-6 (VTA) or B48-15 (VTA1) - Body ground Always 10 kΩ or higher
      B27-4 (VTA2) or B48-16 (VTA2) - Body ground Always 10 kΩ or higher

    4. Reconnect the throttle with motor body assembly connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (THROTTLE POSITION SENSOR - ECM)

    OK

  3. INSPECT ECM (VC VOLTAGE)


    1. Turn the ignition switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      B48-13 (VCTA) - B48-14 (ETA) Ignition switch on (IG) 4.5 to 5.0 V

    NG

    REPLACE ECM Click here

    OK

  4. REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY


    1. Replace the throttle with motor body 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 on (IG) and turn the tester on.

    3. Clear the DTCs Click here.

    4. Start the engine.

    5. With the vehicle stationary, fully depress and release the accelerator pedal.

    6. Allow the engine to idle for 2 seconds or more.

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

    8. Read the DTCs.

      Result
      Display (DTC Output) Proceed to
      P0120, P0121, P0122, P0123, P0220, P0222, P0223 and/or P2135 A
      No output B

    B

    END

    A

    REPLACE ECM Click here