AUDIO AND VISUAL SYSTEM Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

The radio receiver assembly and roof console box assembly (telephone microphone assembly) are connected to each other using the microphone connection detection signal lines.

Using this circuit, the radio receiver assembly sends power to the roof console box assembly (telephone microphone assembly), and the roof console box assembly (telephone microphone assembly) sends microphone signals to the radio receiver assembly.

WIRING DIAGRAM

A01G5UVE17

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK MICROPHONE (OPERATION CHECK)


    1. A01G9BD

      Enter the "Microphone Check" screen. Refer to Check Microphone in Operation Check Click here.

    2. When a voice is input into the microphone, check that the microphone input level meter changes according to the input voice.

    3. Push the recording switch and perform voice recording (w/ Recording Function).

      Tech Tips


      • Select the recording switch with the blower motor of the air conditioning system stopped. If an outlet of the air conditioning system is facing the microphone, noise may be recorded.

      • Voice can be recorded for up to 5 seconds.

    4. Check that the recording indicator remains on while recording and that the recorded voice is played normally without noise or distortion (w/ Recording Function).

      OK
      All check results are normal.

    NG

    REPLACE RADIO RECEIVER ASSEMBLY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - ROOF CONSOLE BOX ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY))


    1. Disconnect the H179 radio receiver assembly connector.

    2. Disconnect the T11 roof console box assembly (telephone microphone assembly) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      H179-4 (MACC) - T11-4 (MACC) Always Below 1 Ω
      H179-5 (MIN+) - T11-3 (MCO+) Always Below 1 Ω
      H179-19 (MIN-) - T11-2 (MCO-) Always Below 1 Ω
      H179-6 (SNS2) - T11-1 (SNS2) Always Below 1 Ω
      H179-4 (MACC) - Body ground Always 10 kΩ or higher
      H179-5 (MIN+) - Body ground Always 10 kΩ or higher
      H179-19 (MIN-) - Body ground Always 10 kΩ or higher
      H179-18 (SGND) - Body ground Always 10 kΩ or higher
      H179-6 (SNS2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT RADIO RECEIVER ASSEMBLY


    1. A01G8PGE07
      Text in Illustration
      *a

      Component with harness connected

      (Radio Receiver Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      H179-4 (MACC) - Body ground Engine switch on (ACC) 4 to 6 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H179-18 (SGND) - Body ground Always Below 1 Ω
      H179-19 (MIN-) - Body ground Always Below 1 Ω

    NG

    REPLACE RADIO RECEIVER ASSEMBLY Click here

    OK

  4. INSPECT ROOF CONSOLE BOX ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)


    1. Remove the roof console box assembly (telephone microphone assembly) Click here.

    2. A01G5WXE61
      Text in Illustration
      *a

      Component without harness connected

      (Roof Console Box Assembly (Telephone Microphone Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (MCO-) - 1 (SNS2) Always Below 1 Ω

    NG

    REPLACE TELEPHONE MICROPHONE ASSEMBLY Click here

    OK

  5. INSPECT ROOF CONSOLE BOX ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)


    1. Turn the engine switch on (ACC).

    2. A01G4ERE39
      Text in Illustration
      *a

      Component with harness connected

      (Roof Console Box Assembly (Telephone Microphone Assembly))

      Connect an oscilloscope to terminals 3 (MCO+) and 2 (MCO-) of the T11 roof console box assembly (telephone microphone assembly) connector.

    3. Check the waveform of the telephone microphone assembly using the oscilloscope.

      Result
      Result Proceed to
      A waveform synchronized with the voice input to the roof console box assembly (telephone microphone assembly) is output A
      A waveform synchronized with the voice input to the roof console box assembly (telephone microphone assembly) is not output B

    B

    REPLACE TELEPHONE MICROPHONE ASSEMBLY Click here

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  6. REPLACE TELEPHONE MICROPHONE ASSEMBLY


    1. Replace the telephone microphone assembly with a new or known good one Click here.

    2. Check if the same malfunction recurs.

      Result
      Result Proceed to

      Malfunction does not recur

      (returns to normal)

      		 A
      Malfunction recurs B

    B

    REPLACE ROOF CONSOLE BOX ASSEMBLY Click here

    A

    END