Brake Control Warning Light Remains ON [10/2015 - ]: Procedure

1. Check if CAN communication system DTCs are output.

   w/ Central Gateway ECU: Refer to DIAGNOSIS SYSTEM [10/2015 - ]

   w/o Central Gateway ECU: Refer to DIAGNOSIS SYSTEM [10/2015 - ]

   Result

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

Result: 

B 

INSPECT CAN COMMUNICATION SYSTEM 

w/ Central Gateway ECU: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - ]

w/o Central Gateway ECU: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - ]

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: 

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	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: 

NG 

CHARGE OR REPLACE AUXILIARY BATTERY 

Result: 

OK 

See step  4

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the Data List on the Techstream (Refer to DATA LIST / ACTIVE TEST [10/2015 - ] ).
   ABS/VSC/TRAC
   
   

   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	-

   *: Electronically Controlled Brake System

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

   Result

   Result	Proceed to
   Display of the Data List remains OFF.	A
   Display of the Data List remains ON.	B

   HINT: 

   If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the parts (Refer to PROBLEM SYMPTOMS TABLE [10/2015 - ] ).

Result: 

A 

INSPECT METER / GAUGE SYSTEM 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - ] )

Result: 

B 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )