Inspection Procedure

1. Check that the steering pad switch can operate the audio system normally.

   OK: 

   Steering pad switch can operate audio system normally. 

OK: REPLACE RADIO AND PLAYER ECU 

NG: GO TO Next Step 

Fig 1: Identifying K56 And K66 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the K56 and K66 ECU connectors.
2. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   K56-9 (TX+) - K66-6 (GTX+)	Below 1 Ω
   K56 - 10 (TX-) - K66-21 (GTX-)	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE RADIO AND PLAYER ECU