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Home >> Lexus >> 2022 >> RX 450hL >> Repair and Diagnosis >> Electrical >> Gauges >> Meter / Gauge System (Diagnostic Codes) (2 Of 2) & Symptom Tests >> Meter / Gauge System >> Circuit Tests >> Speed Signal Circuit [08/2019 - ] >> Procedure

Speed Signal Circuit [08/2019 - ]: Procedure

  1. INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE) 
    1. Disconnect the J10 combination meter assembly connector.
      GTY613189Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Combination Meter Assembly)
    2. Measure the voltage according to the value (s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      J10-19 (+S) - Body ground Power switch on (IG) 4.5 to 14 V

      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

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  2

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE) 
    1. Reconnect the J10 combination meter assembly connector.
    2. Disconnect the A61 skid control ECU assembly connector.
      GTY669087Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Skid Control ECU Assembly)
    3. Measure the voltage according to the value (s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A61-22 (SP1) - Body ground Power switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. INSPECT SKID CONTROL ECU ASSEMBLY (INPUT WAVEFORM) 
    1. Check the input waveform.
      GTY638843Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Combination Meter Assembly)
      1. Reconnect the A61 skid control ECU assembly connector.
      2. Remove the combination meter assembly with the connector (s) still connected.
      3. Connect an oscilloscope to terminal J10-20 (SI) and body ground.
      4. Turn the power switch 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 Power switch on (IG), wheel being rotated

        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

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SKID CONTROL ECU ASSEMBLY) 
    1. Disconnect the J10 combination meter assembly connector.
    2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J10-20 (SI) - A61-22 (SP1) Always Below 1 Ω
      J10-20 (SI) or A61-22 (SP1) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - JUNCTION CONNECTOR) 
    1. Disconnect the J102 junction connector.
    2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J10-19 (+S) - J102-21 Always Below 1 Ω
      J10-19 (+S) or J102-21 - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    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 wire harness and connectors connected to the junction 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.

    2. Measure the voltage according to the value (s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      J103-14 - Body ground Power switch on (IG) 4.5 to 14 V
      J102-19 - Body ground Power switch on (IG) 4.5 to 14 V
      J102-20 - Body ground Power switch on (IG) 4.5 to 14 V
      J103-12 - Body ground* Power switch on (IG) 4.5 to 14 V
      1. *: w/ Navigation ECU

      Result

      Result Proceed to
      Voltage is not present in one circuit A
      Voltage is present in all of 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

      Result System that uses the circuit Proceed to
      J103-12 - Body ground Navigation system*1 A
      J102-20 - Body ground Smart access system with push-button start B
      J102-19 - Body ground Navigation system*1 or Audio and visual system*2 C
      J103-14 - Body ground Navigation system*1 or Audio and visual system*2 D
      1. *1: w/ Navigation ECU
      2. *2: w/o Navigation ECU

    Result: 

    B 

    See step  9

    Result: 

    C 

    See step  10

    Result: 

    D 

    See step  11

    Result: 

    A 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU - BODY GROUND) 
    1. Disconnect the J153 navigation ECU connector.
    2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J153-9 (SPD) or J103-12 - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NAVIGATION ECU. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - BODY GROUND) 
    1. Disconnect the J41 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
      J41-19 (SPD) or J102-20 - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  10. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - BODY GROUND) 
    1. Disconnect the J148*1 or J145*2 radio receiver assembly connector.
    2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J148-27 (SPD) or J102-19 - Body ground*1 Always 10 kΩ or higher
      J145-27 (SPD) or J102-19 - Body ground*2 Always 10 kΩ or higher
      1. *1: w/ Navigation System

        *2: w/o Navigation System

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  11. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - BODY GROUND) 
    1. Disconnect the J66*1 or J156*2 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
      J66-17 (SPD) or J103-14 - Body ground*1 Always 10 kΩ or higher
      J156-11 (SPD) or J103-14 - Body ground*2 Always 10 kΩ or higher
      1. *1: w/ Navigation System

        *2: w/o Navigation System

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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