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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Electrical >> Gauges >> Meter / Gauge System (Except 12.3 Inch Display) - Symptom Tests (2 Of 2) & Circuit Tests >> METER / GAUGE SYSTEM (except 12.3 Inch Display) >> Speed Signal Circuit [11/2023 - ] >> Procedure

Speed Signal Circuit [11/2023 - ]: Procedure

  1. INSPECT COMBINATION METER ASSEMBLY (INPUT WAVEFORM) 
    GTY840625Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Component with harness connected
    (Combination Meter Assembly)
    *b Waveform
    1. Check the signal waveform according to the condition(s) in the table below.
      Item Condition
      Tester connection H21-5 (SI) - Body ground
      Tool setting 5 V/DIV., 20 ms./DIV.
      Condition Ignition switch ON, wheel being rotated

      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

      Result  Proceed to
      The measured waveform is similar to that in the illustration A
      The measured waveform is not similar to that in the illustration
      (Stuck low)      		 B
      The measured waveform is not similar to that in the illustration
      (Stuck high)      		 C

    Result: 

    B 

    See step  6

    Result: 

    C 

    See step  9

    Result: 

    A 

    See step  2

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) 
    GTY910048Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Component with harness connected
    (Combination Meter Assembly)
    *b Waveform
    1. Check the signal waveform according to the condition(s) in the table below.
      Item Condition
      Tester connection H21-6 (+S) - Body ground
      Tool setting 5 V/DIV., 20 ms./DIV.
      Condition Ignition switch ON, wheel being rotated

      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.
      • The waveform (B) changes depending on the connected ECUs.

      Result

      Result  Proceed to
      The measured waveform is similar to that in the illustration A
      The measured waveform is not similar to that in the illustration
      (Stuck low)      		 B
      The measured waveform is not similar to that in the illustration
      (Stuck high)      		 C

    Result: 

    B 

    See step  4

    Result: 

    C 

    REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

    Result: 

    A 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (EACH ECU - COMBINATION METER ASSEMBLY) 
    1. Disconnect the H107 radio and display receiver assembly connector.
    2. Disconnect the M38 stereo component amplifier assembly connector.*
    3. Disconnect the H21 combination meter assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H107-8 (SPD) - H21-6 (+S) Always Below 1 Ω
      M38-11 (SPD) - H21-6 (+S)* Always Below 1 Ω
      1. *: w/ "JBL" Sound System

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    CHECK THE VOLTAGE AT TERMINAL SPD OF EACH ECU 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  4. INSPECT EACH ECU (INTERNAL SHORT) 
    GTY883832Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Component with harness connected
    (Combination Meter Assembly)
    1. Disconnect one of the connectors below.
      NOTE:

      After disconnecting a connector, perform all steps with all other ECUs connected.

      Terminal No. (Symbol) ECU
      H107 Radio and display receiver assembly
      M38* Stereo component amplifier assembly
      1. *: w/ "JBL" Sound System
    2. Measure the voltage according to the value(s) in the table below.
      NOTE:

      Make sure to perform this inspection with the wheels stopped.

      Standard Voltage

      Tester Connection Condition Specified Condition
      H21-6 (+S) - Body ground Ignition switch ON 5 to 14 V
    3. Repeat steps (a) and (b) for each connected ECU.

      HINT: 

      If the voltage changed to the specified voltage after disconnecting a connector, an internal short in the disconnected ECU is suspected.

      Result

      Result  Proceed to
      After performing the inspection procedure for all connectors, the voltage did not change to the specified voltage A
      When disconnecting the connector of the radio and display receiver assembly, the voltage changed to the specified voltage B
      When disconnecting the connector of the stereo component amplifier assembly, the voltage changed to the specified voltage
      (w/ "JBL" Sound System)      		 C

    Result: 

    B 

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

    Result: 

    C 

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

    Result: 

    A 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (EACH ECU - COMBINATION METER ASSEMBLY) 
    1. Disconnect the H107 radio and display receiver assembly connector.
    2. Disconnect the M37 stereo component amplifier assembly connector.*
    3. Disconnect the H21 combination meter assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H107-8 (SPD) or M38-11 (SPD)* - H21-6 (+S) Always Below 1 Ω
      H107-8 (SPD), M38-11 (SPD)* or H21-6 (+S) - Body ground Always 10 kΩ or higher
      1. *: w/ "JBL" Sound System

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  6. CHECK FOR DTC (SMART ACCESS SYSTEM WITH PUSH-BUTTON START (FOR START FUNCTION)) 
    1. Check if smart access system with push-button start (for start function) DTCs are output.

      Body Electrical > Power Source Control > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      DTCs are output B

    Result: 

    B 

    GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START (FOR START FUNCTION) 

    For HV Model: Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2023 - ]

    For Gasoline Model: Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2023 - ]

    Result: 

    A 

    See step  7

  7. INSPECT COMBINATION METER ASSEMBLY 

    HINT: 

    This procedure is performed to check the diode inside the combination meter assembly.

    1. Remove the combination meter assembly.

      Refer to REMOVAL [12/2019 - ]

    2. Measure the internal resistance of the combination meter assembly.

      Standard Resistance

      Tester Connection Tester Connection Condition Measured Value
      H21-39 (IG+) - H21-5 (SI)
      • Positive (+) tester probe → H21-39 (IG+)
      • Negative (-) tester probe → H21-5 (SI)
      		 Always A
      H21-39 (IG+) - H21-5 (SI)
      • Positive (+) tester probe → H21-5 (SI)
      • Negative (-) tester probe → H21-39 (IG+)
      		 Always B

      OK

      There is a large difference between the measured value (A) and the measured value (B).

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - COMBINATION METER ASSEMBLY) 
    1. Disconnect the H138 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the H21 combination meter assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H138-28 (SPDO) or H21-5 (SI) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. CHECK FOR DTC (SMART ACCESS SYSTEM WITH PUSH-BUTTON START (FOR START FUNCTION)) 
    1. Check if smart access system with push-button start (for start function) DTCs are output.

      Body Electrical > Power Source Control > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      DTCs are output B

    Result: 

    B 

    GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START (FOR START FUNCTION) 

    For HV Model: Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2023 - ]

    For Gasoline Model: Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2023 - ]

    Result: 

    A 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - COMBINATION METER ASSEMBLY) 
    1. Disconnect the H138 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the H21 combination meter assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H138-28 (SPDO) - H21-5 (SI) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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