Skid Control ECU Communication Stop Mode [09/2017 - 05/2019]: Procedure

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the brake booster with master cylinder assembly (skid control ECU) connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Brake Booster with Master Cylinder Assembly [Skid Control ECU])

3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A57-37 (CA1H) - A57-38 (CA1L)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR 

Result: 

OK 

See step  2

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A57-28 (GND) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω
   A57-27 (GND2) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω
   A57-26 (GND3) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω
   A57-25 (GND4) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω
   A57-24 (GND5) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω
   A57-23 (GND6) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Brake Booster with Master Cylinder Assembly [Skid Control ECU])

2. Reconnect the cable to the negative (-) auxiliary battery terminal.
   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

   Refer to INITIALIZATION [09/2017 - 05/2019]

3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A57-15 (BS) - Body ground	Power switch off	11 to 14 V
   A57-14 (BI) - Body ground	Power switch off	11 to 14 V
   A57-16 (IG1) - Body ground	Power switch on (IG)	11 to 14 V
   	Power switch off	Below 1 V
   A57-12 (IG2) - Body ground	Power switch on (IG)	11 to 14 V
   	Power switch off	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU). Refer to  REMOVAL [09/2015 - 05/2019] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)