Inspection Procedure

1. Disconnect the RAD NO. 1 and RAD NO. 2 fuses from the engine room No. 1 junction block.
2. Disconnect the ACC fuse from the main body ECU RH.
3. Measure the resistance of the fuses.

   Standard resistance: 

   Below 1 Ω 

NG: REPLACE FUSE 

OK: GO TO Next Step 

1. Disconnect the U29, U31 and U42 amplifier connectors.
2. Measure the resistance of the wire harness side connector.

   Standard resistance: 

   for CD changer models 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   U42-2 (GND) - Body ground	Below 1 Ω
   U42-6 (GND2) - Body ground	Below 1 Ω

   for DVD changer models 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   U31-16 (GND) - Body ground	Below 1 Ω
   U31-15 (GND2) - Body ground	Below 1 Ω

3. Measure the voltage of the wire harness side connectors.

   Standard voltage: 

   for CD changer models 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   U42-1 (+B) - Body ground	Always	10 to 14 V
   U42-3 (+B2) - Body ground	Always	10 to 14 V
   U29-12 (ACC) - Body ground	Power switch ON (ACC)	10 to 14 V

   for DVD changer models 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   U31-1 (+B) - Body ground	Always	10 to 14 V
   U31-10 (+B2) - Body ground	Always	10 to 14 V
   U29-12 (ACC) - Body ground	Power switch ON (ACC)	10 to 14 V

   Fig 1: Identifying U29, U31 And U42 Amplifier Connectors Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE