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Home >> Toyota >> 2005 >> Matrix Base, 4WD >> Repair and Diagnosis (Single Page) >> Engine Performance >> Engine Control System (SFI) (1ZZ-FE(4WD)) - Diagnostics >> SFI System (1ZZ-FE (4WD)) >> DTC P0120, P0122, P0123: Throttle/Pedal Position Sensor/Switch "A" Circuit Low/High Input >> Inspection Procedure
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Inspection Procedure

HINT:

Hand held tester: 

  1. READ VALUE USING HAND HELD TESTER (THROTTLE VALVE OPENING PERCENTAGE) 
    1. Connect a hand-held tester to the DLC3.
    2. Turn the ignition switch to ON and turn the tester ON.
    3. Select the following menu items: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ETCS/THROTTLE POS.
    4. Read the value displayed on the tester when the accelerator pedal is released and depressed.
    Fig 1: Releasing And Depressing Accelerator Pedal
    G02662107Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Result: 

    RESULT REFERENCE

    Throttle Valve Opening Angle (%) Proceed To
    0 (constant) A
    From approximately 0 to 75 B
    Approximately 100 (constant) C

    B:  CHECK FOR INTERMITTENT PROBLEMS  ) 

    C: Go to step   4 

    A: Go to next step. 

  2. INSPECT THROTTLE POSITION SENSOR 
    1. Disconnect the T1 Throttle Position (TP) sensor connector.
    2. Measure the resistance between the terminals of the TP sensor.

      Standard: 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (1 OF 2)

      Tester Connections Throttle Valve Positions Specified Conditions
      VC (T1-1) - E2 (T1-2) - Between 2.5 kΩ and 6.0 kΩ
      VTA (T1-3) - E2 (T1-2) Fully closed Between 0.2 kΩ and 5.7 kΩ
      VTA (T1-3) - E2 (T1-2) Fully open Between 2.0 kΩ and 10.2 kΩ
      Fig 2: Inspecting Throttle Position Sensor Connector
      G02662108Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the TP sensor connector.

    NG: REPLACE THROTTLE POSITION SENSOR 

    OK: Go to next step. 

  3. CHECK HARNESS AND CONNECTOR (ECM - THROTTLE POSITION SENSOR) 
    1. Disconnect the E3 ECM connector.
    2. Measure the resistance between the terminals of the ECM connector.

      Standard: 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (2 OF 2)

      Tester Connections Throttle Valve Positions Specified Conditions
      VC (E3-18) - E2 (E3-28) - Between 2.5 kΩ and 6.0 kΩ
      VTA (E3-21) - E2 (E3-28) Fully closed Between 0.2 kΩ and 5.7 kΩ
      VTA (E3-21) - E2 (E3-28) Fully open Between 2.0 kΩ and 10.2 kΩ
      Fig 3: Disconnecting E3 ECM Connector
      G02662109Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Check the resistance.

      Standard (Check for short): 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (FOR SHORT)

      Tester Connections Specified Conditions
      VC (E3-18) - Body ground 10 kΩ or higher
      VTA (E3-28) - Body ground 10 kΩ or higher
    4. Reconnect the ECM connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM (See  ECM (1ZZ-FE/2ZZ-GE)  ) 

  4. INSPECT THROTTLE POSITION SENSOR 
    1. Disconnect the T1 TP sensor connector.
    2. Measure the resistance between the terminals of the TP sensor.

      Standard: 

      TESTER CONNECTIONS SPECIFIED CONDITIONS

      Tester Connections Throttle Valve Positions Specified Conditions
      VC (T1-1) - E2 (T1-2) - Between 2.5 kΩ and 6.0 kΩ
      VTA (T1-3) - E2 (T1-2) Fully closed Between 0.2 kΩ and 5.7 kΩ
      VTA (T1-3) - E2 (T1-2) Fully open Between 2.0 kΩ and 10.2 kΩ
      Fig 4: Inspecting Throttle Position Sensor Connector
      G02662110Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the TP sensor connector.

    NG: REPLACE THROTTLE POSITION SENSOR 

    OK: Go to next step. 

  5. CHECK HARNESS AND CONNECTOR (ECM - THROTTLE POSITION SENSOR) 
    1. Disconnect the E3 ECM connector.
    2. Disconnect the T1 TP sensor connector.
    3. Check the resistance.
      Fig 5: Disconnecting E3 ECM Connector
      G02662111Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard (Check for open): 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (FOR OPEN)

      Tester Connections Specified Conditions
      VC (T1-1) - VC (E3-18) Below 1 Ω
      VTA (T1-3) - VTA (E3-21) Below 1 Ω
      E2 (T1-2) - E2 (E3-28) Below 1 Ω

      Standard (Check for short): 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (FOR SHORT)

      Tester Connections Specified Conditions
      VC (T1-1) or VC (E3-18) - Body ground 10 kΩ or higher
      VTA (T1-3) or VTA (E3-21) - Body ground 10 kΩ or higher
    4. Reconnect the TP sensor connector.
    5. Reconnect the ECM connector.
Fig 6: Identifying TP Sensor Connector
G02662112Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE ECM (See  ECM (1ZZ-FE/2ZZ-GE)  ) 

OBD II scan tool (excluding the hand-held tester): 

  1. INSPECT THROTTLE POSITION SENSOR 
    1. Disconnect the T1 Throttle Position (TP) sensor connector.
    2. Measure the resistance between the terminals of the TP sensor.

      Standard: 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (1 OF 2)

      Tester Connections Throttle Valve Positions Specified Conditions
      VC (T1-1) - E2 (T1-2) - Between 2.5 kΩ and 6.0 kΩ
      VTA (T1-3) - E2 (T1-2) Fully closed Between 0.2 kΩ and 5.7 kΩ
      VTA (T1-3) - E2 (T1-2) Fully open Between 2.0 kΩ and 10.2 kΩ
      Fig 7: Disconnecting T1 Throttle Position (TP) Sensor Connector
      G02662113Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the TP sensor connector.

    NG: REPLACE THROTTLE POSITION SENSOR 

    OK: Go to next step. 

  2. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM) 
    1. Disconnect the E3 ECM connector.
    2. Measure the resistance between the terminals of the ECM connector.
      Fig 8: Disconnecting E3 ECM Connector
      G02662114Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (2 OF 2)

      Tester Connections Throttle Valve Positions Specified Conditions
      VC (E3-18) - E2 (E3-28) - Between 2.5 kΩ and 6.0 kΩ
      VTA (E3-21) - E2 (E3-28) Fully closed Between 0.2 kΩ and 5.7 kΩ
      VTA (E3-21) - E2 (E3-28) Fully open Between 2.0 kΩ and 10.2 kΩ
    3. Check the resistance.

      Standard (Check for short): 

      TESTER CONNECTIONS SPECIFIED CONDITIONS (FOR SHORT)

      Tester Connections Specified Conditions
      VC (E3-18) - Body ground 10 kΩ or higher
      VTA (E3-28) - Body ground 10 kΩ or higher
    4. Reconnect the ECM connector.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE ECM (See  ECM (1ZZ-FE/2ZZ-GE)  )