Main Body ECU Communication Stop Mode: Procedure

1. Turn the ignition switch off.
   Fig 1: Identifying Main Body ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the F38 main body ECU connector.
3. Measure the resistance according to the value in the table below.

   Standard resistance

   Tester Connection	Switch Condition	Specified Condition
   F38-23 (CANH) - F38-22 (CANL)	Ignition switch off	54 to 69 Ω

4. Reconnect the main body ECU connector.

NG → REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (CAN-H, CAN-L) 

OK: Go to next step 

1. Disconnect the 4B and 4E main body ECU connectors.
   Fig 2: Identifying Wire Harness Connector To Main Body ECU

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

   Standard resistance

   Tester Connection	Condition	Specified Condition
   4E-17 (GND1) - Body ground	Always	Below 1 Ω

3. Measure the voltage according to the value in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   4B-30 (BECU) - Body ground	Always	11 to 14 V

4. Reconnect the main body ECU connectors.
5. Measure the voltage according to the value in the table below.
   Fig 3: Identifying Main Body ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   4B-24 (IG) - Body ground	Ignition switch on	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MAIN BODY ECU