DTC C123A-14: Supply Voltage Circuit IG Open [12/2019 - 11/2023]: Procedure

1. Disconnect the A39 skid control ECU (brake actuator assembly) connector.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A39-45 (IG1) - Body ground	Ignition switch ON	11 to 14 V*1 10.5 to 16 V*2

   *1: w/o Stop and Start System

   *2: w/ Stop and Start System

   Result

   Result	Proceed to
   OK	A
   NG (w/o Stop and Start System)	B
   NG (w/ Stop and Start System)	C

Result: 

A 

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY). Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

B 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

C 

INSPECT STOP AND START SYSTEM (BACKUP BOOST CONVERTER CIRCUIT). Refer to  Backup Boost Converter Circuit [12/2019 - 10/2022]  , or refer to  Backup Boost Converter Circuit [10/2022 - 11/2023]