Mute Signal Circuit between Radio Receiver and Telematics Transceiver [04/2020 - 11/2022]: 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 (DCM (Telematics Transceiver))

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   I143-14 (MUTE) - Body ground	Ignition switch 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 [04/2020 - 09/2022]  , or refer to  PROBLEM SYMPTOMS TABLE [09/2022 - 11/2022] 

Result: 

NG 

See step  2

1. Disconnect the I56 radio and display receiver assembly connector.
2. Disconnect the I143 DCM (telematics transceiver) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I56-3 (TMUT) - I143-14 (MUTE)	Always	Below 1 Ω
   I56-3 (TMUT) or I143-14 (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. Disconnect the I143 DCM (telematics transceiver) 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
   I143-14 (MUTE) - Body ground	Ignition switch ACC	2.0 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE DCM (TELEMATICS TRANSCEIVER). Refer to  REMOVAL [04/2020 - 09/2022]  , or refer to  REMOVAL [09/2022 - 11/2022] 

Result: 

NG 

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY. Refer to  REMOVAL [03/2019 - 09/2022]  , or refer to  REMOVAL [09/2022 - 11/2022]