Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier [04/2013 - 09/2020]: Procedure

1. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   P24-1 (MUTE) - Body ground	Engine switch on (ACC) Audio system playing → Audio system changing modes	2.0 V or higher → Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [04/2013 - 06/2014]  , or refer to  PROBLEM SYMPTOMS TABLE [06/2014 - 10/2016]  , or refer to  PROBLEM SYMPTOMS TABLE [10/2016 - 09/2020] 

Result: 

NG 

See step  2

1. Disconnect the K72 radio receiver assembly connector.
2. Disconnect the P24 stereo component amplifier assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   K72-16 (MUT1) - P24-1 (MUTE)	Always	Below 1 Ω
   K72-16 (MUT1) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Reconnect the P24 stereo component amplifier assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Radio Receiver Assembly)

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   K72-16 (MUT1) - Body ground	Engine switch on (ACC) Audio system playing	2.0 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [04/2013 - 09/2020] 

Result: 

NG 

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [04/2013 - 08/2015]  , or refer to  REMOVAL [08/2015 - 09/2020]