Microphone Circuit between Microphone and Navigation ECU (To 8/2009): Procedure

1. Disconnect the display and navigation module display connector.
   Fig 1: Identifying Display And Navigation Module Display Connector

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2. Disconnect the map light assembly connector.
   Fig 2: Identifying Map Light Assembly Connector

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G4-20 (SNS2) - T10-36 (SNS2)	Always	Below 1 Ω
   G4-4 (MACC) - T10-33 (MACC)	Always	Below 1 Ω
   G4-5 (MIN+) - T10-34 (MCO+)	Always	Below 1 Ω
   G4-6 (MIN-) - T10-35 (MCO-)	Always	Below 1 Ω
   G4-20 (SNS2) - Body ground	Always	10 kΩ or higher
   G4-4 (MACC) - Body ground	Always	10 kΩ or higher
   G4-5 (MIN+) - Body ground	Always	10 kΩ or higher
   G4-6 (MIN-) - Body ground	Always	10 kΩ or higher
   G4-7 (SGND) - Body ground	Always	10 kΩ or higher

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   *1	Front view of wire harness connector (to Display and Navigation Module Display)
   *2	Front view of wire harness connector (to Map Light Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 3: Identifying G4 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   G4-4 (MACC) - Body ground	Engine switch on (ACC)	4 to 6 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G4-7 (SGND) - Body ground	Always	10 kΩ or higher
   G4-6 (MIN-) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Display and Navigation Module Display)

NG → See step   6 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 4: Identifying T10 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   T10-36 (SNS2) - T10-35 (MCO-)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Component without harness connected (Map Light Assembly)

NG → See step   5 

OK: Go to next step 

1. Reconnect the display and navigation module display connector.
2. Reconnect the map light assembly connector.
   Fig 5: Identifying T10 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Turn the engine switch on (ACC).
4. Connect an oscilloscope to terminals 34 (MCO+) and 35 (MCO-) of the map light 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 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
   
   

   *1	Component with harness connected (Map Light Assembly)

NG → See step   5 

OK → See step   8 

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   7 

A → END