AUDIO AND VISUAL SYSTEM(for 8 Speakers) Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

• The radio 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 radio 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 radio receiver assembly.

WIRING DIAGRAM

*a	Shielded
*b	Telephone Microphone Assembly
*c	Map Light Assembly
*d	Radio Receiver Assembly

PROCEDURE

1. CHECK MICROPHONE (OPERATION CHECK)

   
   

   1. 

      Enter the "Microphone Check" screen. Refer to Check Mic & Voice Recognition 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.

      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.

      OK
      All check results are normal.

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE RADIO RECEIVER ASSEMBLY Click here

   NG

2. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - MAP LIGHT ASSEMBLY)

   
   

   1. Disconnect the I121 radio receiver assembly connector.

   2. Disconnect the T7 map light assembly connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition I121-6 (SNS2) - T7-1 (SNS2) Always Below 1 Ω I121-4 (MACC) - T7-4 (MACC) Always Below 1 Ω I121-5 (MIN+) - T7-3 (MCO+) Always Below 1 Ω I121-19 (MIN-) - T7-2 (MCO-) Always Below 1 Ω I121-18 (SGND) - Body ground Always 10 kΩ or higher I121-6 (SNS2) or T7-1 (SNS2) - Body ground Always 10 kΩ or higher I121-4 (MACC) or T7-4 (MACC) - Body ground Always 10 kΩ or higher I121-5 (MIN+) or T7-3 (MCO+) - Body ground Always 10 kΩ or higher I121-19 (MIN-) or T7-2 (MCO-) - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. CHECK RADIO RECEIVER ASSEMBLY

   
   
   1. 

      *a	Component with harness connected (Radio Receiver Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition I121-18 (SGND) - Body ground Always Below 1 Ω I121-19 (MIN-) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition I121-4 (MACC) - Body ground Engine switch on (ACC) 4 to 6 V

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE RADIO RECEIVER ASSEMBLY Click here

   OK

4. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)

   
   

   1. 

      Remove the map light assembly (telephone microphone assembly).

      Click here

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

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

      Result
      Proceed to OK NG

   
   

   NG

   GO TO STEP 6 Click here

   OK

5. CHECK MAP LIGHT ASSEMBLY

   
   
   1. 

      *a	Component with harness connected (Map Light Assembly)

      Reconnect the radio receiver assembly connector.

   2. Turn the engine switch on (ACC).

   3. Connect an oscilloscope to terminals T7-3 (MCO+) and T7-2 (MCO-) of the map light assembly connector.

   4. 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 not output. A A waveform synchronized with the voice input to the map light assembly is output. B

   
   

   B

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

   A

6. CHECK TELEPHONE MICROPHONE ASSEMBLY

   
   

   1. Replace the telephone microphone assembly.

      Click here

   2. Check if the same malfunction recurs.

      OK
      Malfunction disappears.

      Result
      Proceed to OK NG

   
   

   OK

   END (TELEPHONE MICROPHONE ASSEMBLY IS DEFECTIVE)

   NG

   REPLACE MAP LIGHT ASSEMBLY Click here