Brake Control Warning Light Remains ON [10/2018 - ]: Procedure

1. Check if CAN communication system DTCs are output.

   Refer to DIAGNOSIS SYSTEM [10/2018 - 10/2019] , or refer to DIAGNOSIS SYSTEM [10/2019 - 08/2021] , or refer to DIAGNOSIS SYSTEM [08/2021 - 07/2022] , or refer to DIAGNOSIS SYSTEM [07/2022 - ]

   Result

   Result	Proceed to
   DTCs are not output.	A
   DTCs are output.	B

Result: 

B 

INSPECT CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ] 

Result: 

A 

See step  2

1. Check if the skid control ECU (brake booster with master cylinder assembly) connector is securely connected.

   OK

   The connector is securely connected.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT CONNECTOR TO BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CORRECTLY 

Result: 

OK 

See step  3

1. Check the auxiliary battery voltage.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   Auxiliary battery	Power switch on (IG)	11 to 14 V
   Auxiliary battery	Power switch on (READY)	11 to 15.5 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CHARGE OR REPLACE AUXILIARY BATTERY 

Result: 

OK 

See step  4

1. Select the Data List on the Techstream.

   Refer to DATA LIST / ACTIVE TEST [10/2018 - ]

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   ECB Warning Light	Brake warning light / yellow (minor malfunction)	ON or OFF	ON: Warning light on OFF: Warning light off	ECB: Electronically Controlled Brake System

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display
   ECB Warning Light

2. Check the Techstream display condition of the brake warning light / yellow (minor malfunction).

   Result

   Result	Proceed to
   ON is displayed.	A
   OFF is displayed.	B

Result: 

A 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ] 

Result: 

B 

INSPECT METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - 07/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [07/2022 - ]