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Speed Signal Circuit [11/2015 - ]: Procedure

  1. INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE) 
    1. Disconnect the G1 combination meter assembly connector.
      GTY693306Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      G1-39 (+S) - Body ground Ignition switch ON (IG) 4.5 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Combination Meter Assembly)

      HINT: 

      If any of the ECUs specified in the wiring diagram supplies power to the combination meter assembly, the combination meter assembly will output a waveform.

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  2

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE) 
    1. Reconnect the G1 combination meter assembly connector.
    2. Disconnect the A41 brake booster with master cylinder assembly (skid control ECU) connector.
      GTY727146Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A41-11 (SP1) - Body ground Ignition switch ON (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Brake Booster with Master Cylinder Assembly (Skid Control ECU))

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) (INPUT WAVEFORM) 
    1. Check the input waveform.
      GTY730045Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Reconnect the A41 brake booster with master cylinder assembly (skid control ECU) connector.
      2. Remove the combination meter assembly with the connector(s) still connected.
      3. Connect an oscilloscope to terminal G1-40 (SI) and body ground.
      4. Turn the ignition switch to ON (IG).
      5. Turn a wheel slowly.
      6. Check the signal waveform according to the condition(s) in the table below.
        Item Condition
        Tool setting 5 V/DIV., 20 ms./DIV.
        Vehicle condition Wheel being rotated
        TEXT IN ILLUSTRATION

        *a Component with harness connected
        (Combination Meter Assembly)

        OK

        The waveform is similar to that shown in the illustration.

        HINT: 

        When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

    Result: 

    OK 

    REPLACE COMBINATION METER ASSEMBLY 

    Refer to REMOVAL [11/2015 - ] )

    Result: 

    NG 

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) 

    Refer to REMOVAL [11/2015 - ] )

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU)) 
    1. Disconnect the G1 combination meter assembly connector.
    2. Disconnect the A41 brake booster with master cylinder assembly (skid control ECU) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A41-11 (SP1) - G1-40 (SI) Always Below 1 Ω
      A41-11 (SP1) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE COMBINATION METER ASSEMBLY 

    Refer to REMOVAL [11/2015 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - JUNCTION CONNECTOR) 
    1. Disconnect the 3B junction connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G1-39 (+S) - 3B-15 Always Below 1 Ω
      G1-39 (+S) - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR) 
    1. Inspect for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.

      HINT: 

      If voltage is not present, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.

      1. Disconnect the 3A junction connector.
      2. Measure the voltage according to the value(s) in the table below.

        Standard Voltage

        Tester Connection Condition Specified Condition
        3A-16 - Body ground Ignition switch ON (IG) 4.5 to 14 V
        3A-37 - Body ground Ignition switch ON (IG) 4.5 to 14 V
        3A-38 - Body ground Ignition switch ON (IG) 4.5 to 14 V

        Result

        Result Proceed to
        Voltage is not present in one circuit. A
        Voltage is present in all the circuits. B

    Result: 

    B 

    REPLACE JUNCTION CONNECTOR (INSTRUMENT PANEL WIRE) 

    Result: 

    A 

    See step  7

  7. SYSTEM CHECK 
    1. Select the circuit for which voltage was not present in step 6.

      Result

      Tester Connection System that uses the circuit Proceed to
      3A-16 - Body ground Audio and visual system*1 or Navigation system*2 A
      3A-37 - Body ground Smart key system*3 B
      3A-38 - Body ground Vehicle proximity notification system C
      • *1: w/o Navigation System
      • *2: w/ Navigation System
      • *3: w/ Smart Key System

    Result: 

    B 

    See step  9

    Result: 

    C 

    See step  10

    Result: 

    A 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY CIRCUIT, NAVIGATION RECEIVER ASSEMBLY CIRCUIT) 
    1. Disconnect the G41 radio and display receiver assembly*1 or G78 navigation receiver assembly*2.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G41-17 (SPD)*1 - Body ground Always 10 kΩ or higher
      G78-17 (SPD)*2 - Body ground Always 10 kΩ or higher
      • *1: w/o Navigation System
      • *2: w/ Navigation System

      Result

      Result Proceed to
      OK (w/o Navigation System) A
      OK (w/ Navigation System) B
      NG C

    Result: 

    A 

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY 

    Refer to REMOVAL [11/2015 - 06/2017]

    Result: 

    B 

    REPLACE NAVIGATION RECEIVER ASSEMBLY 

    Refer to REMOVAL [11/2015 - 06/2017]

    Result: 

    C 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) CIRCUIT) 
    1. Disconnect the G87 certification ECU (smart key ECU assembly) connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G87-27 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

    Refer to REMOVAL [11/2015 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  10. CHECK HARNESS AND CONNECTOR (VEHICLE APPROACHING SPEAKER CONTROLLER CIRCUIT) 
    1. Disconnect the G82 vehicle approaching speaker controller connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G82-6 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE VEHICLE APPROACHING SPEAKER CONTROLLER 

    Refer to REMOVAL [11/2015 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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