Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier [12/2019 - 10/2022]: 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
   M38-1 (MUTE) - Body ground	Ignition switch ACC, audio system playing → Changing modes	2 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 [12/2019 - 10/2022] 

Result: 

NG 

See step  2

1. Disconnect the H1 radio and display receiver assembly connector.
2. Disconnect the M38 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
   H1-25 (MUT1) - M38-1 (MUTE)	Always	Below 1 Ω
   H1-25 (MUT1) or M38-1 (MUTE) - 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 M38 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 and Display Receiver Assembly)

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   H1-25 (MUT1) - Body ground	Ignition switch ACC, audio system is playing	2 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022] 

Result: 

NG 

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - ]