Mute Signal Circuit between Stereo Component Amplifier and Telematics Transceiver: Procedure

1. Measure the voltage according to the value(s) in the table below.
   Fig 1: Identifying L31 Connector

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   Standard Voltage

   Tester Connection	Condition	Specified Condition
   L31-24 (TMUT) - Body ground	Power switch on (ACC), Audio system is playing → Manual (SOS) switch on, Emergency call mode	Above 3.5 V → Below 1 V

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   *1	Component with harness connected (Stereo Component Amplifier Assembly)

NG → See step   2 

OK → See step   4 

1. Disconnect the L31 stereo component amplifier assembly connector.
   Fig 2: Identifying L31 Stereo Component Amplifier Assembly Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the L19 DCM (telematics transceiver) connector.
   Fig 3: Identifying L19 DCM 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
   L31-24 (TMUT) - L19-17 (MUTE)	Always	Below 1 Ω
   L31-24 (TMUT) - Body ground	Always	10 kΩ or higher

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   *1	Front view of wire harness connector (to Stereo Component Amplifier Assembly)
   *2	Front view of wire harness connector (to DCM (Telematics Transceiver))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the L31 stereo component amplifier assembly connector.
   Fig 4: Identifying L31 Stereo Component Amplifier Assembly Connector

   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
   L31-24 (TMUT) - Body ground	Power switch on (ACC)	Above 3.5 V

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Stereo Component Amplifier Assembly)

NG → See step   6 

OK → See step   5