LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2019 >> RX 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Infotainment >> Navigation System - Diagnostics - Circuit Tests >> Navigation System >> Circuit Tests >> Microphone Circuit [08/2019 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Microphone Circuit [08/2019 - ]: Procedure

  1. CHECK MICROPHONE AND VOICE RECOGNITION (INPUT TO NAVIGATION ECU) 
    1. Enter the "Microphone Check" screen. Refer to Check Microphone (Input to navigation ECU) in Operation Check.

      Refer to OPERATION CHECK [08/2019 - ]

      GTY434237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. When voice is input into the microphone, check that the microphone input level meter changes according to the input voice.

      OK

      Check results are normal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [08/2019 - ] 

    Result: 

    NG 

    See step  2

  2. CHECK MICROPHONE AND VOICE RECOGNITION (INPUT TO RADIO RECEIVER ASSEMBLY) 
    1. Enter the "Microphone Check" screen. Refer to Check Microphone (Input to radio receiver assembly) in Operation Check.

      Refer to OPERATION CHECK [08/2019 - ]

      GTY434237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. When voice is input into the microphone, check that the microphone input level meter changes according to the input voice.

      OK

      Check results are normal.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - NAVIGATION ECU) 
    1. Disconnect the J149 radio receiver assembly connector.
    2. Disconnect the J153 navigation ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J149-25 (MCO+) - J153-13 (MIC+) Always Below 1 Ω
      J149-26 (MCO-) - J153-14 (MIC-) Always Below 1 Ω
      J149-25 (MCO+) or J153-13 (MIC+) - Body ground Always 10 kΩ or higher
      J149-26 (MCO-) or J153-14 (MIC-) - Body ground Always 10 kΩ or higher
      J149-24 (SGND) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. INSPECT RADIO RECEIVER ASSEMBLY (OUTPUT TO NAVIGATION ECU) 
    1. Disconnect the J153 navigation ECU connector.
    2. Turn the engine switch on (ACC).
    3. Check the signal waveform according to the condition(s) in the table below.
      GTY959773Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Navigation ECU)
      Item Condition
      Measurement terminal J153-13 (MIC+) - J153-14 (MIC-)
      Tool setting 50 mV/DIV., 500 ms/DIV.
      Vehicle condition
      1. Turn the engine switch on (ACC).
      2. Sound is input to the telephone microphone assembly when the user is closer than 125 mm from the telephone microphone assembly sound holes in the roof headlining holder cover.

      OK

      The waveform is similar to that shown in the illustration.

      HINT: 

      The oscilloscope waveform shown in the illustration is an example for reference only.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [08/2019 - ] 

    Result: 

    NG 

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

  5. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - TELEPHONE MICROPHONE ASSEMBLY) 
    1. Disconnect the J151 radio receiver assembly connector.
    2. Disconnect the U15 telephone microphone assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J151-25 (SNS2) - U15-3 (SNS2) Always Below 1 Ω
      J151-25 (SNS2) or U15-3 (SNS2) - 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 (RADIO RECEIVER ASSEMBLY - DCM (TELEMATICS TRANSCEIVER)) 
    1. Disconnect the J151 radio receiver assembly connector.
    2. Disconnect the J157 DCM (telematics transceiver) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J151-21 (MIN+) - J157-16 (MCO+) Always Below 1 Ω
      J151-22 (MIN-) - J157-32 (MCO-) Always Below 1 Ω
      J151-21 (MIN+) or J157-16 (MCO+) - Body ground Always 10 kΩ or higher
      J151-22 (MIN-) or J157-32 (MCO-) - Body ground Always 10 kΩ or higher
      J151-24 (SGND) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - TELEPHONE MICROPHONE ASSEMBLY) 
    1. Disconnect the J157 DCM (telematics transceiver) connector.
    2. Disconnect the U15 telephone microphone assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J157-5 (MCVD) - U15-1 (MACC) Always Below 1 Ω
      J157-6 (MCI+) - U15-2 (MCO+) Always Below 1 Ω
      J157-7 (MCI-) - U15-4 (MCO-) Always Below 1 Ω
      J157-5 (MCVD) or U15-1 (MACC) - Body ground Always 10 kΩ or higher
      J157-6 (MCI+) or U15-2 (MCO+) - Body ground Always 10 kΩ or higher
      J157-7 (MCI-) or U15-4 (MCO-) - Body ground Always 10 kΩ or higher
      J157-23 (SGND) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK DCM (TELEMATICS TRANSCEIVER) 
    1. Remove the DCM (telematics transceiver) with the connector(s) still connected.
      GTY961617Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (DCM (Telematics Transceiver))
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      J157-5 (MCVD) - Body ground Engine switch on (ACC) 4 to 6 V
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J157-23 (SGND) - Body ground Always Below 1 Ω
      J157-7 (MCI-) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE DCM (TELEMATICS TRANSCEIVER). Refer to  REMOVAL [08/2019 - ] 

    Result: 

    OK 

    See step  9

  9. CHECK TELEPHONE MICROPHONE ASSEMBLY (OUTPUT TO DCM (TELEMATICS TRANSCEIVER)) 
    GTY959598Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Component with harness connected
    (Telephone Microphone Assembly)
    1. Check the output waveform.
      1. Remove the telephone microphone assembly with the connector(s) still connected.

        Refer to REMOVAL [08/2019 - ]

      2. Connect an oscilloscope to terminal U15-2 (MCO+) and U15-4 (MCO-).
      3. Turn the engine switch on (ACC).
      4. Sound is input to the telephone microphone assembly when the user is closer than 125 mm from the telephone microphone assembly sound holes in the roof headlining holder cover.
      5. Check the signal waveform according to the condition(s) in the table below.
        Item Condition
        Measurement terminal U15-2 (MCO+) - U15-4 (MCO-)
        Tool setting 50 mV/DIV., 500 ms/DIV.
        Vehicle condition
        1. Engine switch on (ACC)
        2. Sound is input to the telephone microphone assembly when the user is closer than 125 mm from the telephone microphone assembly sound holes in the roof headlining holder cover.

        OK

        The waveform is similar to that shown in the illustration.

        HINT: 

        The oscilloscope waveform shown in the illustration is an example for reference only.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE TELEPHONE MICROPHONE ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

    Result: 

    OK 

    See step  10

  10. CHECK DCM (TELEMATICS TRANSCEIVER) (OUTPUT TO RADIO RECEIVER ASSEMBLY) 
    GTY961924Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Component with harness connected
    (DCM [Telematics Transceiver])
    1. Check the output waveform.
      1. Remove the DCM (telematics transceiver) with the connector(s) still connected.

        Refer to REMOVAL [08/2019 - ]

      2. Connect an oscilloscope to terminal J157-16 (MCO+) and J157-32 (MCO-).
      3. Turn the engine switch on (ACC).
      4. Sound is input to the telephone microphone assembly when the user is closer than 125 mm from the telephone microphone assembly sound holes in the roof headlining holder cover.
      5. Check the signal waveform according to the condition(s) in the table below.
        Item Condition
        Measurement terminal J157-16 (MCO+) - J157-32 (MCO-)
        Tool setting 50 mV/DIV., 500 ms/DIV.
        Vehicle condition
        1. Engine switch on (ACC)
        2. Sound is input to the telephone microphone assembly when the user is closer than 125 mm from the telephone microphone assembly sound holes in the roof headlining holder cover.

        OK

        The waveform is similar to that shown in the illustration.

        HINT: 

        The oscilloscope waveform shown in the illustration is an example for reference only.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPLACE DCM (TELEMATICS TRANSCEIVER). Refer to  REMOVAL [08/2019 - ] 

scientia non olet · About LEMON Manuals