NAVIGATION SYSTEM Microphone Circuit between Microphone and Navigation Receiver Assembly

DESCRIPTION


WIRING DIAGRAM

A005BAIE66
*a (Shielded)
*b Map Light Assembly (Telephone Microphone Assembly)
*c Navigation ECU Sub-assembly

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU SUB-ASSEMBLY - MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY))


    1. Disconnect the L38 navigation ECU sub-assembly connector.

    2. Disconnect the U3 map light assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L38-4 (MACC) - U3-2 (MACC) Always Below 1 Ω
      L38-5 (MIN+) - U3-3 (MCO+) Always Below 1 Ω
      L38-19 (MIN-) - U3-4 (MCO-) Always Below 1 Ω
      L38-6 (SNS2) - U3-5 (SNS2) Always Below 1 Ω
      L38-4 (MACC) - Body ground Always 10 kΩ or higher
      L38-5 (MIN+) - Body ground Always 10 kΩ or higher
      L38-19 (MIN-) - Body ground Always 10 kΩ or higher
      L38-18 (SGND) - Body ground Always 10 kΩ or higher
      L38-6 (SNS2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT NAVIGATION ECU SUB-ASSEMBLY


    1. Reconnect the L38 navigation ECU sub-assembly connector.

    2. Reconnect the U3 map light assembly (telephone microphone assembly) connector.

    3. A005DA0E02
      Text in Illustration
      *a

      Component with harness connected

      (Navigation ECU Sub-assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L38-4 (MACC) - Body ground Power switch on (ACC) 4 to 6 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L38-18 (SGND) - Body ground Always Below 1 Ω
      L38-19 (MIN-) - Body ground Always Below 1 Ω

    OK

    REPLACE NAVIGATION ECU SUB-ASSEMBLY Click here

    NG

  3. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)


    1. Disconnect the U3 map light assembly connector.

    2. A005CM9E02
      Text in Illustration
      *a

      Component without harness connected

      (Map Light Assembly (Telephone Microphone Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U3-5 (SNS2) - U3-4 (MCO-) Always Below 1 Ω

    NG

    REPLACE TELEPHONE MICROPHONE ASSEMBLY Click here

    OK

  4. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)


    1. Reconnect the L38 navigation ECU sub-assembly connector.

    2. A005EC0E02
      Text in Illustration
      *a

      Component with harness connected

      (Map Light Assembly (Telephone Microphone Assembly))

      Reconnect the U3 map light assembly connector.

    3. Turn the power switch on (ACC).

    4. Connect an oscilloscope to terminals 3 (MCO+) and 4 (MCO-) of the U3 map light assembly connector.

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

      Result
      Result Proceed to
      A waveform synchronized with the voice input to the map light assembly is output A
      A waveform synchronized with the voice input to the map light assembly is not output B

    A

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

    B

  5. REPLACE TELEPHONE MICROPHONE ASSEMBLY


    1. Replace the telephone microphone assembly Click here.

    2. Check if the same malfunction recurs.

      Result
      Result Proceed to

      Malfunction does not recur

      (returns to normal)

      		 A
      Malfunction recurs B

    A

    END

    B

    REPLACE MAP LIGHT ASSEMBLY Click here