Mute Signal Circuit between Radio Receiver and Multi-media Interface ECU: Procedure

1. Measure the voltage according to the value(s) in the table below.
   Fig 1: Identifying F40 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   F40-6 (MUTE) - Body ground	Engine switch on (ACC), USB audio system is playing → Mode is changing	Above 2.5 V → Below 0.5 V

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Radio Receiver Assembly)

NG → See step   2 

OK → See step   4 

1. Disconnect the F40 radio receiver assembly and L35 multi-media interface ECU connectors.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F40-6 (MUTE) - L35-6 (MUT1)	Always	Below 1 Ω
   F40-6 (MUTE) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the L35 multi-media interface ECU connector.
   Fig 2: Identifying L35 Connector

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   L35-6 (MUT1) - Body ground	Engine switch on (ACC)	Above 2.5 V

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Multi-media Interface ECU)

NG → See step   5 

OK → See step   6