Microphone Circuit between Microphone and Radio Receiver: Procedure

1. Disconnect the radio receiver assembly connector.
   Fig 1: Measuring Voltage Of Radio Receiver Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   E32-3 (MACC) - Body ground	Ignition switch ON	4 to 6 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Radio Receiver Assembly)

NG → See step   6 

OK: Go to next step 

1. Disconnect the telephone microphone assembly and radio receiver assembly connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q11-4 (SNS2) - E32-1 (SNS2)	Always	Below 1 Ω
   Q11-3 (MIC+) - E32-2 (MIN+)	Always	Below 1 Ω
   Q11-5 (MIC-) - E32-5 (MIN-)	Always	Below 1 Ω
   Q11-1 (MACC) - E32-3 (MACC)	Always	Below 1 Ω
   Q11-4 (SNS2) - Body ground	Always	10 kΩ or higher
   Q11-3 (MIC+) - Body ground	Always	10 kΩ or higher
   Q11-5 (MIC-) - Body ground	Always	10 kΩ or higher
   Q11-1 (MACC) - Body ground	Always	10 kΩ or higher
   E32-6 (SGND) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 2: Checking Resistance Of Telephone Microphone Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q11-4 (SNS2) - Q11-5 (MIC-)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Telephone Microphone Assembly)

NG → See step   7 

OK: Go to next step 

1. Check that the malfunction disappears when a known good telephone microphone assembly is installed. Refer to REMOVAL .

   OK

   Malfunction disappears.

NG → See step   5 

OK → END (TELEPHONE MICROPHONE ASSEMBLY WAS DEFECTIVE)