Mute Signal Circuit between Stereo Component Amplifier and Telematics Transceiver [11/2017 - 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 (DCM (Telematics Transceiver))

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   O65-17 (MUTE) - Body ground	Engine switch on (ACC), audio system playing → Emergency call mode	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 [11/2017 - 03/2019]  , or refer to  PROBLEM SYMPTOMS TABLE [03/2019 - 09/2020] 

Result: 

NG 

See step  2

1. Disconnect the T20 stereo component amplifier assembly connector.
2. Disconnect the O65 DCM (telematics transceiver) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   T20-2 (TMUT) - O65-17 (MUTE)	Always	Below 1 Ω
   T20-2 (TMUT) or O65-17 (MUTE) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS AND CONNECTOR 

Result: 

OK 

See step  3

1. Reconnect the T20 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 DCM (Telematics Transceiver))

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   O65-17 (MUTE) - Body ground	Engine switch on (ACC)	2.0 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE DCM (TELEMATICS TRANSCEIVER). Refer to  REMOVAL [11/2017 - 09/2020] 

Result: 

NG 

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [09/2014 - ]