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

1. Measure the voltage according to the value(s) in the table below.
   Fig 1: Inspecting Multi-Media Interface ECU

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   E31-6 (MUT1) - Body ground	Ignition switch ACC, USB audio system or satellite radio playing → Changing sources	Above 3.5 V → Below 1 V

   TEXT IN ILLUSTRATION
   
   

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

NG → See step   2 

OK → See step   4 

1. Disconnect the E15 navigation receiver assembly connector.
2. Disconnect the E31 multi-media interface ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E15-6 (MUTE) - E31-6 (MUT1)	Always	Below 1 Ω
   E15-6 (MUTE) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the multi-media interface ECU and check that the malfunction disappears, refer to REMOVAL .

   OK

   Malfunction disappears.

NG → See step   5 

OK → END (MULTI-MEDIA INTERFACE ECU IS DEFECTIVE)