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Home >> Lexus >> 2017 >> GX 460 Base >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Meter / Gauge / Display System (Diagnostic Codes & Symptom Tests) >> Meter / Gauge System >> Speed Signal Circuit [08/2015 - 08/2017] >> Procedure

Speed Signal Circuit [08/2015 - 08/2017]: Procedure

  1. CHECK ECU TERMINAL VOLTAGE (INPUT VOLTAGE) 
    1. Disconnect the G3 meter connector.
      GTY617835Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      G3-32 (+S) - Body ground Engine switch on (IG) 4.5 to 14 V
      TEXT IN ILLUSTRATION

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

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  2

  2. CHECK COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE) 
    1. Disconnect the A7 master cylinder solenoid (skid control ECU) connector.
      GTY623358Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A7-12 (SP1) - Body ground Engine switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Master Cylinder Solenoid [Skid Control ECU])

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. CHECK COMBINATION METER ASSEMBLY (SPEED SIGNAL) 
    1. Check the input waveform.
      GTY681217Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Reconnect the G3 meter connector.
      2. Remove the combination meter assembly with the connector(s) still connected.
      3. Connect an oscilloscope to terminal G3-33 (SI) and body ground.
      4. Turn the engine switch on (IG).
      5. Check the signal waveform according to the condition(s) in the table below.
        MEASUREMENT CONDITION

        Item Condition
        Tester Connection G3-33 (SI) - Body ground
        Tool setting 5 V/DIV., 20 ms./DIV.
        Condition Driving at approximately 20 km/h (12 mph)

        OK

        The waveform displayed is as 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 [08/2015 - 08/2019] )

    Result: 

    NG 

    REPLACE MASTER CYLINDER SOLENOID (SKID CONTROL ECU) 

    (Refer to DISASSEMBLY [08/2015 - ] )

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SKID CONTROL ECU) 
    1. Disconnect the G3 meter connector.
    2. Disconnect the A7 master cylinder solenoid (skid control ECU) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G3-33 (SI) - A7-12 (SP1) Always Below 1 Ω
      A7-12 (SP1) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE COMBINATION METER ASSEMBLY 

    (Refer to REMOVAL [08/2015 - 08/2019] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - NO. 3 JUNCTION BLOCK) 
    1. Disconnect the G3 meter connector.
    2. Disconnect the 3A junction block connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G3-32 (+S) - 3A-24 Always Below 1 Ω
      G3-32 (+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 (NO. 3 JUNCTION BLOCK) 
    1. Inspect for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.

      HINT: 

      If the voltage is not as specified, 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 3C junction block connector.
        GTY657978Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *A for 17 Speakers *B w/ Rain Sensor
        *1 No. 3 Junction Block - -
        *a Front view of wire harness connector
        (to No. 3 Junction Block)        		 - -
      2. Measure the voltage according to the value(s) in the table below.

        Standard Voltage

        Tester Connection Switch Condition Specified Condition
        3A-48 - Body ground*1 Engine switch on (IG) 4.5 to 14 V
        3C-23 - Body ground*2 Engine switch on (IG) 4.5 to 14 V
        3A-84 - Body ground Engine switch on (IG) 4.5 to 14 V
        3A-72 - Body ground Engine switch on (IG) 4.5 to 14 V
        1. *1: for 17 Speakers
        2. *2: w/ Rain Sensor
        RESULT

        Result Proceed to
        Voltage is not as specified in one circuit A
        Voltage is as specified in all circuits B

    Result: 

    B 

    REPLACE NO. 3 JUNCTION BLOCK 

    Result: 

    A 

    See step  7

  7. SYSTEM CHECK 
    1. Select the circuit for which the voltage was not as specified in the previous step.
      RESULT

      Tester Connection System that Uses the Circuit Proceed to
      3C-23 - Body ground Wiper and washer system*1 A
      3A-48 - Body ground Audio and visual system*2 B
      3A-84 - Body ground Audio and visual system, navigation system*3 C
      3A-72 - Body ground SFI system, tire pressure warning system, safety connect system*4, smart access system with push-button start D
      1. *1: w/ Rain Sensor
      2. *2: for 17 Speakers
      3. *3: w/ Navigation System
      4. *4: w/ Safety Connect System

    Result: 

    B 

    See step  9

    Result: 

    C 

    See step  10

    Result: 

    D 

    See step  14

    Result: 

    A 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - WINDSHIELD WIPER SWITCH ASSEMBLY) 
    1. Disconnect the G50 windshield wiper switch connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G50-6 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY 

    (Refer to REMOVAL [08/2015 - 08/2019] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the R31 stereo component amplifier connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      R31-17 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY 

    (Refer to REMOVAL [08/2015 - 08/2021] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  10. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - JUNCTION CONNECTOR) 
    1. Disconnect the 3A junction block connector.
    2. Disconnect the H48 junction connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3A-84 - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  11

  11. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR) 
    1. Inspect for a short in the circuit that is connected to the junction connector shown in the wiring diagram.
      1. Disconnect the H49 junction block connector.
        GTY661075Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *a Front view of wire harness connector
        (to Junction Connector)
      2. Measure the voltage according to the value(s) in the table below

        Standard Voltage

        Tester Connection Switch Condition Specified Condition
        H49-10 - Body ground Engine switch on (IG) 4.5 to 14 V
        H49-11 - Body ground Engine switch on (IG) 4.5 to 14 V
        RESULT

        Result Proceed to
        NG (H49-10 - Body ground) A
        NG (H49-11 - Body ground) B
        OK C

    Result: 

    B 

    See step  13

    Result: 

    C 

    REPLACE JUNCTION CONNECTOR 

    Result: 

    A 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - MULTI-MEDIA MODULE RECEIVER ASSEMBLY) 
    1. *1: w/ Navigation System
    2. *2: w/o Navigation System
    1. Disconnect the H11*1 or H3*2 multi-media module receiver assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H11-56 (SPD) - Body ground*1 Always 10 kΩ or higher
      H3-17 (SPD) - Body ground*2 Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE MULTI-MEDIA MODULE RECEIVER ASSEMBLY 

    (Refer to REMOVAL [08/2015 - 08/2021] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  13. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the H21 stereo component amplifier assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H21-17 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY 

    (Refer to REMOVAL [08/2015 - 08/2021] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  14. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - NO. 4 JUNCTION BLOCK) 
    1. Disconnect the 3A junction block connector.
    2. Disconnect the 4A junction block connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3A-72 - 4A-58 Always Below 1 Ω
      3A-72 - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  15

  15. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK) 
    1. Inspect for a short in the circuit that is connected to the junction connector shown in the wiring diagram.
      1. Disconnect the 4A junction block connector.
      2. Disconnect the 4B junction block connector.
        GTY646843Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *A w/ Safety Connect System - -
        *1 No. 4 Junction Block - -
        *a Front view of wire harness connector
        (to No. 4 Junction Block)        		 - -
      3. Measure the voltage according to the value(s) in the table below

        Standard Voltage

        Tester Connection Switch Condition Specified Condition
        4B-11 - Body ground Engine switch on (IG) 4.5 to 14 V
        4B-45 - Body ground* Engine switch on (IG) 4.5 to 14 V
        4A-46 - Body ground Engine switch on (IG) 4.5 to 14 V
        4A-93 - Body ground Engine switch on (IG) 4.5 to 14 V
        1. *: w/ Safety Connect System

    Result: 

    OK 

    REPLACE NO. 4 JUNCTION BLOCK 

    Result: 

    NG 

    See step  16

  16. SYSTEM CHECK 
    1. Select the circuit for which the voltage was not as specified in the previous step.
      RESULT

      Tester Connection System that Uses the Circuit Proceed to
      4B-11 - Body ground Smart access system with push-button start A
      4B-45 - Body ground Safety connect system* B
      4A-46 - Body ground Tire pressure warning system C
      4A-93 - Body ground SFI system D
      1. *: w/ Safety Connect System

    Result: 

    B 

    See step  18

    Result: 

    C 

    See step  19

    Result: 

    D 

    See step  20

    Result: 

    A 

    See step  17

  17. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK - POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the G39 power management control ECU connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G39-23 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE POWER MANAGEMENT CONTROL ECU 

    (Refer to REMOVAL [08/2015 - 08/2019] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  18. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK - TELEMATICS TRANSCEIVER) 
    1. Disconnect the G56 telematics transceiver connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G56-10 (SPDP) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE TELEMATICS TRANSCEIVER 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  19. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK - TIRE PRESSURE WARNING ECU AND RECEIVE) 
    1. Disconnect the R2 tire pressure warning ECU and receiver connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      R2-2 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER 

    (Refer to REMOVAL [08/2015 - 08/2017] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  20. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK - ECM) 
    1. Disconnect the G44 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G44-18 (SPD) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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