NAVIGATION SYSTEM Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

• The multi-media module receiver assembly and map light assembly (telephone microphone assembly) are connected to each other using the microphone connection detection signal lines.

• Using this circuit, the multi-media module receiver assembly sends power to the map light assembly (telephone microphone assembly), and the map light assembly (telephone microphone assembly) sends microphone signals to the multi-media module receiver assembly.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MULTI-MEDIA MODULE RECEIVER ASSEMBLY -MAP LIGHT ASSEMBLY)

   
   

   1. Disconnect the F77 multi-media module receiver assembly connector.

   2. Disconnect the R7 map light assembly connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition F77-27 (MIN+) - R7-27 (MI1+) Always Below 1 Ω F77-29 (MACC) - R7-25 (ACC) Always Below 1 Ω F77-48 (MIN-) - R7-26 (MIC-) Always Below 1 Ω F77-49 (SNS2) - R7-20 (SNS2) Always Below 1 Ω F77-27 (MIN+) - Body ground Always 10 kΩ or higher F77-28 (SGND) - Body ground Always 10 kΩ or higher F77-29 (MACC) - Body ground Always 10 kΩ or higher F77-48 (MIN-) - Body ground Always 10 kΩ or higher F77-49 (SNS2) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

2. CHECK MULTI-MEDIA MODULE RECEIVER ASSEMBLY

   
   
   1. 

      Text in Illustration

      *a	Component with harness connected (Multi-media Module Receiver Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition F77-29 (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 F77-28 (SGND) - Body ground Always Below 1 Ω F77-48 (MIN-) - Body ground Always Below 1 Ω

   
   

   NG

   REPLACE MULTI-MEDIA MODULE RECEIVER ASSEMBLY Click here

   OK

3. INSPECT MAP LIGHT ASSEMBLY

   
   

   1. 

      Remove the map light assembly Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 20 (SNS2) - 26 (MIC-) Always Below 1 Ω

   
   

   NG

   CHECK TELEPHONE MICROPHONE ASSEMBLY Click here

   OK

4. CHECK MAP LIGHT ASSEMBLY

   
   
   1. 

      Text in Illustration

      *a	Component with harness connected (Map Light Assembly)

      Turn the engine switch on (ACC).

   2. Connect an oscilloscope to terminals R7-27 (MI1+) and R7-26 (MIC-) of the map light 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 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. CHECK TELEPHONE MICROPHONE ASSEMBLY

   
   

   1. Replace the telephone microphone assembly with a new or normally functioning 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

   
   

   A

   END (TELEPHONE MICROPHONE ASSEMBLY IS DEFECTIVE)

   B

   REPLACE MAP LIGHT ASSEMBLY Click here