Microphone Circuit between Microphone and Radio Receiver: Procedure

1. Disconnect the radio receiver assembly connector.
   Fig 1: Inspecting Radio Receiver Assembly E41 Connector Terminals

   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
   E41-3 (MACC) - Body ground	Ignition switch ACC	4 to 6 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Radio Receiver Assembly)

NG → See step   7 

OK: Go to next step 

1. Disconnect the map light assembly*1 or telephone microphone assembly*2 and radio receiver assembly connectors.
   • *1: w/ Sliding Roof
   • *2: w/o Sliding Roof
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   W/O SLIDING ROOF
   
   

   Tester Connection	Condition	Specified Condition
   O7-3 (SNS2) - E41-1 (SNS2)	Always	Below 1 Ω
   O7-2 (MIC+) - E41-2 (MIC+)	Always	Below 1 Ω
   O7-4 (MIC-) - E41-5 (MIC-)	Always	Below 1 Ω
   O7-1 (MACC) - E41-3 (MACC)	Always	Below 1 Ω
   O7-3 (SNS2) - Body ground	Always	10 kΩ or higher
   O7-2 (MIC+) - Body ground	Always	10 kΩ or higher
   O7-4 (MIC-) - Body ground	Always	10 kΩ or higher
   O7-1 (MACC) - Body ground	Always	10 kΩ or higher
   E41-6 (SGND) - Body ground	Always	10 kΩ or higher

   W/ SLIDING ROOF
   
   

   Tester Connection	Condition	Specified Condition
   O4-9 (SNS2) - E41-1 (SNS2)	Always	Below 1 Ω
   O4-11 (MIC+) - E41-2 (MIC+)	Always	Below 1 Ω
   O4-10 (MIC-) - E41-5 (MIC-)	Always	Below 1 Ω
   O4-12 (ACC) - E41-3 (MACC)	Always	Below 1 Ω
   O4-9 (SNS2) - Body ground	Always	10 kΩ or higher
   O4-11 (MIC+) - Body ground	Always	10 kΩ or higher
   O4-10 (MIC-) - Body ground	Always	10 kΩ or higher
   O4-12 (ACC) - Body ground	Always	10 kΩ or higher
   E41-6 (SGND) - Body ground	Always	10 kΩ or higher

3. Proceed to the next step based on the inspection result.

   Result

   Result	Proceed to
   OK (w/ Sliding Roof)	A
   OK (w/o Sliding Roof)	B
   NG	C

B → See step   9 

C → REPAIR OR REPLACE HARNESS OR CONNECTOR 

A: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 2: Inspecting Map Light Assembly O4 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O4-9 (SNS2) - O4-10 (MIC-)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Map Light Assembly)

NG → See step   5 

OK: Go to next step 

1. Reconnect the radio receiver assembly connector.
2. Reconnect the map light assembly connector.
3. Turn the ignition switch to ACC.
4. Connect an oscilloscope to terminals 11 (MIC+) and 10 (MIC-) of the map light assembly connector.
   Fig 3: Inspecting Map Light Assembly O4 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Check the waveform of the map light assembly using an 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

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Map Light Assembly)

B → See step   5 

A → See step   6 

1. Replace the telephone microphone assembly. Refer to REMOVAL .
2. Check if the same malfunction recurs.

   Result

   Result	Proceed to
   Malfunction does not recur (returns to normal)	A
   Malfunction recurs	B

B → See step   8 

A → END