Inspection Procedure

1. Remove the RADIO NO. 1, P RR-IG2 and P-ACC fuses from the passenger side junction block.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   FUSE (RADIO NO. 1, P RR-IG2, P-ACC)
   
   

   Tester Connection	Condition	Specified Condition
   RADIO NO. 1 fuse	Always	Below 1 Ω
   P RR-IG2 fuse	Always	Below 1 Ω
   P-ACC fuse	Always	Below 1 Ω

NG: REPLACE FUSE 

OK: GO TO NEXT STEP 

1. Disconnect the R24 ECU connector.
2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard voltage 

   ECU - VEHICLE BATTERY AND BODY GROUND STANDARD VOLTAGE
   
   

   Tester Connection	Switch Condition	Specified Condition
   R24-1 (+B) - Body ground	Always	11 to 14 V
   R24-13(IG2)-Body ground	Engine switch on (IG)	11 to 14 V
   R24-14 (ACC) - Body ground	Engine switch on (ACC)	11 to 14 V

   Fig 1: Identifying R24 ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance 

   ECU - VEHICLE BATTERY AND BODY GROUND STANDARD RESISTANCE
   
   

   Tester Connection	Condition	Specified Condition
   R24-12(E)-Body ground	Always	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE MAYDAY ECU TOGETHER WITH MAYDAY BATTERY AND THEN PERFORM REGISTRATION