AUDIO AND VISUAL SYSTEM Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

This circuit sends the voice signal from the telephone microphone assembly to the radio receiver.

It also supplies power from the radio receiver to the telephone microphone assembly.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   INSPECT RADIO RECEIVER

   
   
   1. 

      Disconnect the radio receiver connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition E26-3 (MACC) - Body ground Ignition switch ON 4 to 6 V

      Table 1. Text in Illustration

      *a	Component without harness connected (Radio Receiver)

   
   
   • OKClick here
   • NGClick here
2. Click here

   CHECK HARNESS AND CONNECTOR (TELEPHONE MICROPHONE ASSEMBLY - RADIO RECEIVER)

   
   

   1. Disconnect the telephone microphone assembly and radio receiver connectors.

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

      Standard Resistance

      Tester Connection Condition Specified Condition Q15-4 (SNS2) - E26-1 (SNS2) Always Below 1 Ω Q15-3 (MIC+) - E26-2 (MIN+) Always Below 1 Ω Q15-5 (MIC-) - E26-5 (MIN-) Always Below 1 Ω Q15-1 (MACC) - E26-3 (MACC) Always Below 1 Ω Q15-4 (SNS2) - Body ground Always 10 kΩ or higher Q15-3 (MIC+) - Body ground Always 10 kΩ or higher Q15-5 (MIC-) - Body ground Always 10 kΩ or higher Q15-1 (MACC) - Body ground Always 10 kΩ or higher E26-6 (SGND) - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NGClick here
3. Click here

   INSPECT TELEPHONE MICROPHONE ASSEMBLY

   
   
   1. 

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

      Standard Resistance
      Tester Connection Condition Specified Condition Q15-4 (SNS2) - Q15-5 (MIC-) Always Below 1 Ω

      Table 2. Text in Illustration

      *a	Component without harness connected (Telephone Microphone Assembly)

   
   
   • OKClick here
   • NGClick here
4. Click here

   INSPECT TELEPHONE MICROPHONE ASSEMBLY

   
   

   1. Reconnect the radio receiver connector.

   2. 

      Reconnect the telephone microphone assembly connector.

   3. Turn the ignition switch to ACC.

   4. Connect an oscilloscope to terminals 3 (MIC+) and 5 (MIC-) of the telephone microphone assembly connector.

   5. Check the waveform of the telephone microphone assembly using an 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 is not output B

      Table 3. Text in Illustration

      *a	Component with harness connected (Telephone Microphone Assembly)

   
   
   • AClick here
   • BClick here
5. Click here

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

6. Click here

   REPLACE RADIO RECEIVERClick here

7. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR

8. Click here

   REPLACE TELEPHONE MICROPHONE ASSEMBLYClick here