ANTI-LOCK BRAKE SYSTEM > Brake Warning Light Remains ON

for Preparation Click here


DESCRIPTION

The skid control ECU 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 connector is disconnected from the skid control ECU.
  2. The brake fluid level is insufficient.
  3. The parking brake is applied.
  4. EBD operation has been disabled.

WIRING DIAGRAM


C181567E01


INSPECTION PROCEDURE

1.CHECK CAN COMMUNICATION SYSTEM

  1. Check if a CAN communication system DTC is output (Click here).

    Result:

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


B
INSPECT CAN COMMUNICATION SYSTEM (Click here)
A


2.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


3.CHECK BATTERY

  1. Check the battery voltage.

    Standard Voltage:
    11 to 14 V


NG
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY (for 2ZR-FE) (Click here)
OK


4.INSPECT SKID CONTROL ECU (IG1 TERMINAL)


    C156384E72

  1. Disconnect the skid control ECU connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A51-34 (IG1) - Body ground
    		Ignition switch ON
    		11 to 14 V


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


5.INSPECT SKID CONTROL ECU (GND1 TERMINAL)


    C156384E71

  1. Turn the ignition switch off.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A51-1 (GND1) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)
OK


6.READ VALUE USING TECHSTREAM (PARKING BRAKE SWITCH)

  1. Reconnect the skid control ECU connector.

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Select Data List mode on the Techstream (Click here).

    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
    		-

  1. Using the Techstream, check the switch operation when the parking brake is operated.

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


NG
Go to step 10
OK


7.INSPECT BRAKE FLUID LEVEL WARNING SWITCH
C178470E01

  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 (E)
    		Switch OFF (Float up)
    		1.9 to 2.1 kΩ
    1 (+) - 2 (E)
    		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.


NG
REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH) (Click here)
OK


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


    C158617E05

  1. Disconnect the combination meter connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E46-40 (SW) - A12-1 (+)
    		Always
    		Below 1 Ω
    E46-40 (SW) - Body ground
    		Always
    		10 kΩ or higher
    A12-2 (E) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.INSPECT COMBINATION METER ASSEMBLY

  1. Perform the Active Test of the combination meter (meter CPU) using the Techstream (Click here).

  1. Check the combination meter.

    HINT:
    Reinstall the connectors and restore the vehicle to its prior condition before checking the combination meter.

    OK:
    The brake warning light turns on or off in accordance with the Techstream.

    HINT:
    If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part (Click here).


NG
REPLACE COMBINATION METER ASSEMBLY (Click here)
OK

REPLACE BRAKE ACTUATOR ASSEMBLY (Click here)  

10.INSPECT PARKING BRAKE SWITCH
C164441E01

  1. Turn the ignition switch off.

  1. Disconnect the parking brake switch connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    1 - Body ground
    		Parking brake switch ON
    (Switch pin free)
    		Below 1 Ω
    1 - Body ground
    		Parking brake switch OFF
    (Switch pin pushed in)
    		10 kΩ or higher


NG
REPLACE PARKING BRAKE SWITCH (Click here)
OK


11.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - PARKING BRAKE SWITCH)


    C154934E01

  1. Disconnect the main body ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2C-5 (PKB) - E12-1
    		Always
    		Below 1 Ω
    2C-5 (PKB) - Body ground
    		Always
    		10 kΩ or higher

    HINT:
    If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part (Click here).


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)