Mute Signal Circuit between Radio Receiver and Extension Module: Procedure

1. Measure the voltage according to the value(s) in the table below.
   Fig 1: b1 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   b1-1 (MUTE) - Body ground	Ignition switch ACC, audio system is playing → Changing modes	Above 3.5 V → Below 1 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Extension Module)

NG → See step   2 

OK → See step   4 

1. Disconnect the radio and display receiver assembly connector.
2. Disconnect the extension module connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   b3-6 (MUTE) - b1-1 (MUTE)	Always	Below 1 Ω
   b3-6 (MUTE) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the radio and display receiver assembly connector.
2. Measure the voltage according to the value(s) in the table below.
   Fig 2: b1 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   b1-1 (MUTE) - Body ground	Ignition switch ACC, audio system is playing	Above 3.5 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Extension Module)

NG → See step   6 

OK → See step   5