Anti-Lock Brake System (For Hatchback) Brake Warning Light Remains On

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

CHECK CAN COMMUNICATION SYSTEM

INSPECT BATTERY

CHECK TERMINAL VOLTAGE (IG1 TERMINAL)

CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

READ VALUE USING TECHSTREAM (PARKING BRAKE SWITCH)

INSPECT BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH)

CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE FLUID LEVEL WARNING SWITCH)

READ VALUE USING TECHSTREAM (BRAKE WARNING LIGHT)

REPLACE COMBINATION METER ASSEMBLY

INSPECT COMBINATION METER ASSEMBLY

INSPECT PARKING BRAKE SWITCH ASSEMBLY

CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - PARKING BRAKE SWITCH)

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

ANTI-LOCK BRAKE SYSTEM (for Hatchback) - Brake Warning Light Remains ON


DESCRIPTION

The skid control ECU (brake actuator assembly) is connected to the combination meter via CAN communication.
If any of the following is detected, the brake warning light remains on:
  1. The skid control ECU (brake actuator assembly) connector is disconnected from the skid control ECU (brake actuator assembly).
  2. The brake fluid level is insufficient.
  3. The parking brake is applied.
  4. EBD operation is not possible.

WIRING DIAGRAM


Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan).Anti-Lock Brake System (For Hatchback) Brake Warning Light Remains On


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

  1. Check if the skid control ECU connector is securely connected.

    OK:
    The connector is securely connected.


NG
CONNECT CONNECTOR TO ECU CORRECTLY
OK


2.CHECK CAN COMMUNICATION SYSTEM

  1. Check if CAN communication system DTCs are output (YARIS_NCP93 RM000001RSW02LX.html).

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


B
CHECK CAN COMMUNICATION SYSTEM (YARIS_NCP93 RM000001RSO05UX.html)
A


3.INSPECT BATTERY

  1. Check the battery voltage.

    Standard voltage:
    11 to 14 V


NG
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY (YARIS_NCP93 RM000001GNJ010X.html)
OK


4.CHECK TERMINAL VOLTAGE (IG1 TERMINAL)

  1. Disconnect the skid control ECU (brake actuator assembly) connector.

  1. Turn the ignition switch to ON.



    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan).Anti-Lock Brake System (For Hatchback) Brake Warning Light Remains On

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A71-34 (IG1) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid control ECU)

  1. Turn the ignition switch off.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK


5.CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan).Anti-Lock Brake System (For Hatchback) Brake Warning Light Remains On

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A71-1 (GND1) - Body ground
    		Always
    		Below 1 Ω
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Skid control ECU)

  1. Reconnect the skid control ECU (brake actuator assembly) connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK


6.READ VALUE USING TECHSTREAM (PARKING BRAKE SWITCH)

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

  1. According to the display on the Techstream, read the Data List.

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

  1. 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.


NG
Go to step 12
OK


7.INSPECT BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH)


    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan).Anti-Lock Brake System (For Hatchback) Brake Warning Light Remains On

  1. Turn the ignition switch off.

  1. Remove the reservoir filler cap and strainer.

  1. Disconnect the brake fluid level warning switch connector.

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

    HINT:
    A float is located inside the reservoir. Its position can be changed by increasing or decreasing the level of brake fluid.
    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    1 - 2
    		Switch off (Float up)
    		10 kΩ or higher
    Switch on (Float down)
    		Below 1 Ω
    HINT:
    If there is no problem after finishing the above check, adjust the brake fluid level to the MAX level.
Text in Illustration
*a
Component without harness connected
(Brake Fluid Level Warning Switch)

  1. Reconnect the brake fluid level warning switch connector.

  1. Reinstall the reservoir filler cap and strainer.



NG
REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (YARIS_NCP93 RM0000023TK01BX.html)
OK


8.CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE FLUID LEVEL WARNING SWITCH)

  1. Disconnect the combination meter assembly connector and the brake fluid level warning switch.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D100-12 (SW) - A62-1 (+)
    		Always
    		Below 1 Ω
    A62-2 (E) - Body ground
    		Always
    		Below 1 Ω
    D100-12 (SW) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the combination meter assembly connector and the brake fluid level warning switch.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.READ VALUE USING TECHSTREAM (BRAKE WARNING LIGHT)

  1. Turn the ignition switch off.

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

  1. According to the display on the Techstream, read the Data List.

    ABS/VSC/TRAC
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Brake Warning Light
    		Brake warning light / OFF or ON
    		OFF
    		-

  1. When performing the Brake Warning Light Active Test, check Brake Warning Light in the Data List.


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
Changes between ON and OFF
A
Does not change between ON and OFF
B
OFF
Changes between ON and OFF
A
Does not change between ON and OFF
B

  1. Connect the Techstream to the DLC3.



B
REPLACE BRAKE ACTUATOR ASSEMBLY (YARIS_NCP93 RM000001BXP02KX.html)
A


10.REPLACE COMBINATION METER ASSEMBLY

  1. Turn the ignition switch off.

  1. Replace the combination meter assembly (YARIS_NCP93 RM0000035EJ00BX.html).


NEXT


11.INSPECT COMBINATION METER ASSEMBLY

  1. Connect the Techstream to the DLC3.

  1. Perform Active Test of the combination meter assembly using the Techstream (YARIS_NCP93 RM000001F8Q018X.html).

    OK:
    The brake warning light turns ON or OFF in accordance with the Techstream.


NG
REPLACE BRAKE ACTUATOR ASSEMBLY (YARIS_NCP93 RM000001BXP02KX.html)
OK

END

12.INSPECT PARKING BRAKE SWITCH ASSEMBLY

  1. Remove the parking brake switch assembly (YARIS_NCP93 RM000001C4X01NX.html).

  1. Inspect the parking brake switch assembly (YARIS_NCP93 RM000001C4U01NX.html).



NG
REPLACE PARKING BRAKE SWITCH ASSEMBLY (YARIS_NCP93 RM000001C4X01NX.html)
OK


13.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - PARKING BRAKE SWITCH)

  1. Disconnect the instrument panel junction block assembly connector and the parking brake switch assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3A-28 (PKB) - D116-1
    		Always
    		Below 1 Ω
    3A-28 (PKB) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the instrument panel junction block assembly connector and the parking brake switch assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


14.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

  1. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

  1. Disconnect the instrument panel junction block assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3A-28 -12 (PKB)
    		Always
    		Below 1 Ω
    3A-28 - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the instrument panel junction block assembly connector.

  1. Reinstall the main body ECU (multiplex network body ECU) to the instrument panel junction block assembly.



NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (YARIS_NCP93 RM000003TOE00CX.html)