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Home >> Lexus >> 2013 >> GX 460 Base >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Meter / Gauge / Display (Diagnostic Codes & Symptom Tests) >> Meter / Gauge System >> Symptom Tests >> Speed Signal Circuit >> Procedure

Speed Signal Circuit: Procedure

  1. CHECK ECU TERMINAL VOLTAGE (INPUT VOLTAGE) 
    1. Disconnect the G3 meter connector.
      GTY274920Courtesy 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)

    NG → See step   5 

    OK: Go to next step 

  2. CHECK COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE) 
    1. Disconnect the A7 master cylinder solenoid (skid control ECU) connector.
      GTY260362Courtesy 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])

    NG → See step   4 

    OK: Go to next step 

  3. CHECK COMBINATION METER ASSEMBLY (SPEED SIGNAL) 
    1. Check the input waveform.
      GTY274064Courtesy 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 approx. 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.

    NG → See step   29 

    OK → See step   22 

  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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   24 

  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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  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.
        GTY257910Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *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
        3C-23 - Body ground Engine switch on (IG) 4.5 to 14 V
        3A-48 - Body ground* 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
        • *: for 14 Speakers
        RESULT

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

    B → REPLACE NO. 3 JUNCTION BLOCK 

    A: Go to next step 

  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 Auto wiper system A
      3A-48 - Body ground Audio and visual system*1 B
      3A-84 - Body ground Audio and visual system*2 or 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: for 14 Speakers
      • *2: for 9 Speakers
      • *3: w/ Navigation System
      • *4: w/ Safety Connect System

    B → See step   9 

    C → See step   10 

    D → See step   15 

    A: Go to next step 

  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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   23 

  9. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the R34 stereo component amplifier connector.
    2. Measure the resistance according to the value(s) in the table below.
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      R34-2 (SPD) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   31 

  10. CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK - JUNCTION CONNECTOR) 
    1. Disconnect the 3A junction block connector.
    2. Disconnect the H22 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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  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 H23 junction block connector.
        GTY278218Courtesy 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
        H23-10 - Body ground Engine switch on (IG) 4.5 to 14 V
        H23-11 - Body ground Engine switch on (IG) 4.5 to 14 V
        RESULT

        Result Proceed to
        NG (H23-10 - Body ground) A
        NG (H23-11 - Body ground) B
        OK C

    B → See step   14 

    C → REPLACE JUNCTION CONNECTOR 

    A: Go to next step 

  12. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - RADIO RECEIVER ASSEMBLY) 
    NOTE:

    For vehicles with a navigation system, proceed to next step.

    1. Disconnect the H30 radio receiver connector.
    2. Measure the resistance according to the value(s) in the table below.
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      H30-3 (SPD) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   26 

  13. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - DISPLAY AND NAVIGATION MODULE DISPLAY) 
    1. Disconnect the H4 display and navigation module display connector.
    2. Measure the resistance according to the value(s) in the table below.
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      H4-18 (SPD) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   27 

  14. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the H10*1 or H25*2 stereo component amplifier assembly connector.
      • *1: w/ Navigation System
      • *2: w/o Navigation System
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      W/ NAVIGATION SYSTEM

      Tester Connection Condition Specified Condition
      H10-2 (SPD) - Body ground Always 10 kΩ or higher
      W/O NAVIGATION SYSTEM

      Tester Connection Condition Specified Condition
      H25-11 (SPD) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   30 

  15. 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 (+S) - 4A-58 Always Below 1 Ω
      3A-72 (+S) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  16. 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.
        GTY411556Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        TEXT IN ILLUSTRATION

        *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
        • *: w/ Safety Connect System
        RESULT

        Result Proceed to
        NG (4B-11, 4B-45 or 4A-46 - Body ground) A
        NG (4A-93 - Body ground) B
        OK C

    B → See step   21 

    C → REPLACE NO. 4 JUNCTION BLOCK 

    A: Go to next step 

  17. 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
      • *: w/ Safety Connect System

    B → See step   19 

    C → See step   20 

    A: Go to next step 

  18. 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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   25 

  19. 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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE TELEMATICS TRANSCEIVER 

  20. CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK - TIRE PRESSURE WARNING ECU) 
    1. Disconnect the R2 tire pressure warning ECU 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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE TIRE PRESSURE WARNING ECU 

  21. 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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   28 

  22. REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [06/2012 - ] 
  23. REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY. Refer to  REMOVAL [06/2012 - ] 
  24. REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [06/2012 - ] 
  25. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL [06/2012 - ] 
  26. REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [06/2012 - ] 
  27. REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY. Refer to  REMOVAL [06/2012 - ] 
  28. REPLACE ECM. Refer to  REMOVAL [06/2012 - ] 
  29. REPLACE MASTER CYLINDER SOLENOID (SKID CONTROL ECU). Refer to  DISASSEMBLY [06/2012 - ] 
  30. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [06/2012 - ] 
  31. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [06/2012 - ] 
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