ECU Power Source Circuit: Procedure

1. Remove the ECU-IG NO. 1 fuse from the instrument panel junction block.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   ECU-IG NO. 1	Always	Below 1 Ω

NG → See step   4 

OK: Go to next step 

1. Disconnect the D33 ECU connector.
   Fig 1: Checking Harness And Connector (ECU - Battery)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   D33-7 (IG) - Body ground	Ignition switch on (IG)	11 to 14 V
   	Ignition switch off	Below 1 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the D33 ECU connector.
   Fig 2: Checking Harness And Connector (ECU - Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D33-9 (GND) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   5 

1. Disconnect the D33 ECU connector.
   Fig 3: Checking Harness And Connector (ECU - Fuse)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D33-7 (IG) - Body ground	Always	10 kΩ or higher

NG → REPLACE FUSE AND REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE FUSE