ECU Power Source Circuit: Wiring Diagram

1. Remove the ECU-B fuse from the engine room R/B and J/B.
2. Remove the IGN fuse from the driver side J/B.
3. Measure the resistance of the fuse.

   Standard resistance: Below 1Ω 

4. Reinstall fuses.

NG: REPLACE FUSE 

OK: Go to next step 

1. Remove the ignition switch.
2. Measure the resistance of the switch.

   Standard resistance 

   IGNITION SWITCH ASSEMBLY
   
   

   Tester Connection	Switch Condition	Specified Condition
   (AM2) - 6 (IG2)	LOCK, ACC	10 kΩ or higher
   	ON, START	Below 1 Ω

   Fig 2: Inspecting Ignition Switch Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE IGNITION SWITCH ASSEMBLY 

OK: Go to next step 

1. Disconnect the T10 ECU connector.
2. Measure the resistance and voltage of the wire harness side connector.

   Standard resistance 

   TRANSPONDER KEY ECU ASSEMBLY - BATTERY AND BODY GROUND (RESISTANCE)
   
   

   Tester Connection	Condition	Specified Condition
   T10-16 (GND) - Body ground	Always	Below 1 Ω

   Standard voltage 

   TRANSPONDER KEY ECU ASSEMBLY - BATTERY AND BODY GROUND (VOLTAGE)
   
   

   Tester Connection	Condition	Specified Condition
   T10-1 (+B) - Body ground	Always	10 to 14 V
   T10-2 (IG) - Body ground	Ignition switch OFF	Below 1 V
   	Ignition switch ON	10 to 14 V

   Fig 3: Checking Harness And Connector (Transponder Key ECU Assembly - Battery And Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Reconnect the ECU connector.

NG: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR 

OK: REPLACE TRANSPONDER KEY ECU ASSEMBLY