Steering Control ECU Communication Stop Mode [11/2017 - ]: Procedure

1. Disconnect the cable from the negative (-) battery terminal.
2. Disconnect the O16 front steering control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Front Steering Control ECU)

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O16-3 (CNH1) - O16-9 (CNL1)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω
   O16-2 (CNH2) - O16-8 (CNL2)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

   Result

   Result
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (FRONT STEERING CONTROL ECU) 

Result: 

OK 

See step  2

1. Disconnect the A56 front steering control ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Front Steering Control ECU)

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A56-1 (PGND) - Body ground	Cable disconnected from negative (-) battery terminal	Below 1 Ω
   O16-13 (PGD2) - Body ground	Cable disconnected from negative (-) battery terminal	Below 1 Ω

3. Reconnect the cable to the negative (-) battery terminal.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A56-2 (PIG) - Body ground	Always	11 to 14 V
   O16-7 (+BI) - Body ground	Always	11 to 14 V
   O16-4 (IG) - Body ground	Engine switch on (IG)	11 to 14 V

   Result

   Result
   OK
   NG

Result: 

OK 

REPLACE FRONT STEERING CONTROL ECU. Refer to  REMOVAL [09/2014 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)