Brake Warning Light Remains ON [08/2019 - ]: Procedure

1. Check for DTCs (Refer to DTC CHECK / CLEAR [08/2019 - ] ).
   RESULT
   
   

   Result	Proceed to
   DTC is not output	A
   DTC is output	B

Result: 

B 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2019 - ] 

Result: 

A 

See step  2

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus (Refer to DIAGNOSIS SYSTEM [08/2019 - 08/2021] , or refer to DIAGNOSIS SYSTEM [08/2021 - 08/2022] , or refer to DIAGNOSIS SYSTEM [08/2022 - ] ).

   OK

   CAN bus Check indicates no malfunctions in CAN communication.

Result: 

NG 

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] 

Result: 

OK 

See step  3

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Parking Brake SW	Parking brake switch/ ON or OFF	ON: Parking brake applied OFF: Parking brake released	-

6. Using the Techstream, check the input of the switch operation when the parking brake pedal is operated.

   OK

   When the parking brake is operated, the display changes as shown above.

Result: 

NG 

See step  5

Result: 

OK 

See step  4

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Brake Warning Light	Brake warning light/ ON or OFF	ON: Warning light on OFF: Warning light off	-

6. When performing the Brake Warning Light Active Test, check Brake Warning Light in the Data List (Refer to DATA LIST / ACTIVE TEST [08/2019 - ] ).
   ABS/VSC/TRAC
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Brake Warning Light	Brake warning light	Warning light ON/OFF	Observe the combination meter.

   RESULT
   
   

   Result		Proceed to
   Data List Display	Data List Display when Performing Active Test ON/OFF Operation
   ON	Does not change between ON and OFF	A
   	Changes between ON and OFF	B
   OFF	Does not change between ON and OFF	A
   	Changes between ON and OFF	B

Result: 

A 

REPLACE MASTER CYLINDER SOLENOID. Refer to  DISASSEMBLY [08/2015 - ] 

Result: 

B 

GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - ] 

1. Disconnect the A2 parking brake switch connector.
2. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   1 - Body ground	Parking brake applied (Switch pin not pushed in)	Below 1 Ω
   	Parking brake released (Switch pin pushed in)	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Parking Brake Switch)

Result: 

NG 

REPLACE PARKING BRAKE SWITCH ASSEMBLY. Refer to  REMOVAL [08/2019 - ] 

Result: 

OK 

See step  6

1. Disconnect the A2 parking brake switch connector.
2. Disconnect the 2N main body ECU (driver side junction block assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A2-1 - 2N-16 (PKB)	Always	Below 1 Ω
   A2-1 - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR