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

DESCRIPTION

• The radio receiver assembly and 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 telephone microphone assembly, and the telephone microphone assembly sends microphone signals to the radio receiver assembly.

WIRING DIAGRAM

*a	(Shielded)
*b	Telephone Microphone Assembly
*c	Radio Receiver Assembly

PROCEDURE

1. CHECK MICROPHONE (OPERATION CHECK)

   
   

   1. 

      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.

      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 - TELEPHONE MICROPHONE ASSEMBLY)

   
   

   1. Disconnect the J53 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 J53-6 (SNS2) - U15-3 (SNS2) Always Below 1 Ω J53-4 (MACC) - U15-1 (MACC) Always Below 1 Ω J53-5 (MIN+) - U15-2 (MCO+) Always Below 1 Ω J53-19 (MIN-) - U15-4 (MCO-) Always Below 1 Ω J53-6 (SNS2) or U15-3 (SNS2) - Body ground Always 10 kΩ or higher J53-4 (MACC) or U15-1 (MACC) - Body ground Always 10 kΩ or higher J53-5 (MIN+) or U15-2 (MCO+) - Body ground Always 10 kΩ or higher J53-19 (MIN-) or U15-4 (MCO-) - Body ground Always 10 kΩ or higher J53-18 (SGND) - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. INSPECT RADIO RECEIVER ASSEMBLY

   
   

   1. Reconnect the J53 radio receiver assembly connector.

   2. Reconnect the U15 telephone microphone assembly connector.

   3. 

      *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 J53-4 (MACC) - Body ground Engine 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 J53-18 (SGND) - Body ground Always Below 1 Ω J53-19 (MIN-) - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE RADIO RECEIVER ASSEMBLY Click here

   OK

4. INSPECT TELEPHONE MICROPHONE ASSEMBLY

   
   

   1. Remove the telephone microphone assembly.

      Click here

   2. 

      *a	Component without harness connected (Telephone Microphone Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition 3 (SNS2) - 4 (MCO-) Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   OK

5. INSPECT TELEPHONE MICROPHONE ASSEMBLY

   
   

   1. Reconnect the J53 radio receiver assembly connector.

   2. Reconnect the U15 telephone microphone assembly connector.

   3. Turn the engine switch on (ACC).

   4. 

      *a	Component with harness connected (Telephone Microphone Assembly)

      Connect an oscilloscope to terminals 2 (MCO+) and 4 (MCO-) of the U15 telephone microphone 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 telephone microphone assembly is output. A A waveform synchronized with the voice input to the telephone microphone assembly is not output. B

   
   

   A

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

   B

   REPLACE TELEPHONE MICROPHONE ASSEMBLY Click here