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

DTC Code DTC Name
P0120 Throttle / Pedal Position Sensor / Switch "A" Circuit
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 Electronic Throttle Control System (ETCS) does not use a throttle cable.

  • This throttle position sensor is a non-contact type.

The throttle position sensor is mounted on the throttle body and it detects the opening angle of the throttle valve. This sensor is electronically controlled and uses Hall-effect elements so that accurate control and reliability can be obtained. The throttle position sensor has 2 sensor elements / signal outputs: VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and VTA2 is used to detect a malfunction in VTA1. Voltage applied to VTA1 and VTA2 changes between 0 to 5 V in proportion to the opening angle of the throttle valve. The ECM performs several checks to confirm proper operation of the throttle position sensor and VTA1.

The ECM judges the actual opening angle of the throttle valve using signals input from terminals VTA1 and VTA2. Then the ECM controls the throttle motor, which controls the throttle valve angle properly in response to operation of the accelerator pedal.

A01J73EE36
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 body)


  • ECM
P0122

Output voltage of VTA1 0.2 V or less for 2 seconds

(1 trip detection logic)

  • Throttle position sensor (built into throttle body)


  • Short in VTA1 circuit


  • Open in VC circuit


  • ECM
P0123

Output voltage of VTA1 4.8 V or more for 2 seconds

(1 trip detection logic)

  • Throttle position sensor (built into throttle body)


  • Open in VTA1 circuit


  • Open in E2 circuit


  • Short between VC 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 body)


  • ECM
P0222

Output voltage of VTA2 0.5 V or less for 2 seconds

(1 trip detection logic)

  • Throttle position sensor (built into throttle body)


  • Short in VTA2 circuit


  • Open in VC circuit


  • ECM
P0223 Output voltage of VTA2 4.8 V or more, and VTA1 between 0.2 V and 1.8 V for 2 seconds (1 trip detection logic)

  • Throttle position sensor (built into throttle body)


  • Open in VTA2 circuit


  • Open in E2 circuit


  • Short between VC and VTA2 circuits


  • ECM
P2135

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

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

(b) Output voltage of VTA1 0.2 V or less, and VTA2 0.5 V or less, for 0.4 seconds or more

  • Short between VTA1 and VTA2 circuits


  • Throttle position sensor (built into throttle body)


  • ECM

Note

When a malfunction is detected, the throttle valve is locked at a certain opening angle. Also, all electronically controlled throttle operations are canceled until the system returns to normal and the ignition switch is turned OFF.

Tech Tips


  • When any of these DTCs is detected, check the throttle valve opening angle (Throttle Position and Throttle Position No. 2) using the intelligent tester.

  • The Throttle Position is the VTA1 signal (expressed as a percentage), and Throttle Position No. 2 is the VTA2 signal (expressed as a voltage).

Reference (Normal condition):
Tester Display Accelerator Pedal Fully Released Accelerator Pedal Fully Depressed
Throttle Position 10 to 24% 64 to 96%
Throttle Position No. 2 2.1 to 3.1 V 4.5 to 5.5 V

MONITOR DESCRIPTION

The ECM uses the throttle position sensor to monitor the throttle valve opening angle.

(a) There is a specific voltage difference expected between VTA1 and VTA2 for each throttle opening angle.

If the difference between VTA1 and VTA2 is incorrect, the ECM interprets this as a fault and will set a DTC.

(b) VTA1 and VTA2 each have a specific voltage opening range.

If VTA1 or VTA2 is out of the normal operating range, the ECM interprets this as a fault and will set a DTC.

(c) VTA1 and VTA2 should never have similar voltage levels.

If VTA1 is within 0.02 V of VTA2, the ECM interprets this as a short circuit in the throttle position sensor system and will set a DTC.

This monitor runs for 2 seconds (the first 2 seconds of engine idle) after the engine is started (1 trip detection logic).

FAIL-SAFE

If the ETCS is malfunctioning, the ECM cuts off the current to the throttle actuator. The throttle control valve returns to a predetermined throttle position (approximately 6°) by the force of the return spring.

Then, required engine power is calculated by using the ignition timing and accelerator pedal position. The engine is controlled by intermittent fuel cut.

If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven at minimum speed. If the accelerator pedal is depressed quickly, the vehicle may speed up and slow down erratically.

WIRING DIAGRAM

A01J7NKE07

INSPECTION PROCEDURE

Tech Tips


  • If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

  • These DTCs are related to the throttle position sensor.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (THROTTLE POSITION, THROTTLE POSITION NO. 2)


    1. Connect the intelligent tester to the DLC3.

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

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

    4. Read the values.

      Result

      TP (VTA1)

      When AP Released

      TP No. 2 (VTA2)

      When AP Released

      TP (VTA1)

      When AP Depressed

      TP No. 2 (VTA2)

      When AP Depressed

      		 Suspected Area Proceed to
      0% 0 to 0.2 V 0% 0 to 0.2 V VC circuit open A
      100% 4.5 to 5.0 V 100% 4.5 to 5.0 V E2 circuit open A
      0 or 100%

      2.1 to 3.1 V

      (fail-safe)

      		 0 or 100%

      2.1 to 3.1 V

      (fail-safe)

      		 VTA1 circuit open or ground short A

      10 to 24%

      (fail-safe)

      0 to 0.2 V,

      or 4.5 to 5.0 V

      10 to 24%

      (fail-safe)

      0 to 0.2 V,

      or 4.5 to 5.5 V

      		 VTA2 circuit open or ground short A
      10 to 24% 2.1 to 3.1 V

      64 to 96%

      (not fail-safe)

      4.5 to 5.0 V

      (not fail-safe)

      		 Throttle position sensor circuit is normal B

      Tech Tips


      • TP stands for throttle position, and AP stands for accelerator pedal.

      • VTA1 is expressed as a percentage, and VTA2 is expressed as a voltage.


    B

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

    A

  2. CHECK WIRE HARNESS (THROTTLE POSITION SENSOR - ECM)

    A01J6XRE12

    1. Disconnect the T1 throttle body connector.

    2. Disconnect the E15 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      T1-5 (VC) - E15-23 (VC) Below 1 Ω
      T1-6 (VTA1) - E15-20 (VTA1) Below 1 Ω
      T1-4 (VTA2) - E15-19 (VTA2) Below 1 Ω
      T1-3 (E2) - E15-28 (E2) Below 1 Ω
      T1-5 (VC) or E15-23 (VC) -Body ground 10 kΩ or higher
      T1-6 (VTA1) or E15-20 (VTA1) - Body ground 10 kΩ or higher
      T1-4 (VTA2) or E15-19 (VTA2) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  3. CHECK ECM (VC VOLTAGE)

    A01J6AVE28

    1. Disconnect the throttle body connector.

    2. Turn the ignition switch ON.

    3. Measure the voltage of the ECM connector.

      Standard voltage
      Tester Connection Specified Condition
      E15-23 (VC) - E15-28 (E2) 4.5 to 5.0 V

    NG

    REPLACE ECM

    OK

  4. REPLACE THROTTLE BODY


    NEXT

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


    1. Clear the DTCs Click here.

    2. Start the engine.

    3. Idle engine for 15 seconds or more.

    4. Connect the intelligent tester to the DLC3.

    5. Turn the tester ON.

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

    7. Read the DTCs.

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

    B

    SYSTEM OK

    A

    REPLACE ECM