Inspection Procedure

1. Remove the ECU-B fuse from the engine room junction block.
2. Remove the ACC and IGN fuses from the cowl side junction block RH.
3. Measure the resistance of the fuses.

   Standard resistance: 

   Below 1 Ω 

NG : REPLACE FUSE 

OK : Go to Next Step 

1. Disconnect the U45 ECU connector.
2. Measure the voltage and resistance of the wire harness side connector.

   Standard voltage 

   VOLTAGE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   U45-1 (+B) - Body ground	Always	10 to 14 V
   U45-13 (IG2) - Body ground	Engine switch on (IG)	10 to 14 V
   U45-14 (ACC) - Body ground	Engine switch on (ACC)	10 to 14 V

   Standard resistance 

   RESISTANCE REFERENCE
   
   

   Tester Connection	Specified Condition
   U45-12 (E) - Body ground	Below 1 Ω

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

Fig 1: Identifying U45 ECU Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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