ELECTRONICALLY CONTROLLED 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 / red (malfunction) 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


C209426E06


INSPECTION PROCEDURE

NOTICE:
When replacing the brake booster with master cylinder (skid control ECU), perform initialization and calibration of the linear solenoid valve (Click here).

1.CHECK DTC

  1. Check if a ABS, VSC and/or electronically controlled brake system DTC is output (Click here).

    Result:

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



B
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS (Click here)
A


2.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


3.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


4.CHECK AUXILIARY BATTERY

  1. Check the auxiliary battery voltage.

    Standard Voltage:
    11 to 14 V



NG
CHARGE OR REPLACE AUXILIARY BATTERY
OK


5.INSPECT SKID CONTROL ECU (IG1 TERMINAL)


    C209401E67

  1. Disconnect the skid control ECU connector.

  1. Turn the power switch on (IG).

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A61-16 (IG1) - Body ground
    		Power switch on (IG)
    		11 to 14 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Skid Control ECU)



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


6.INSPECT SKID CONTROL ECU (GND TERMINAL)


    C209401E60

  1. Turn the power switch off.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A61-28 (GND) - Body ground
    		Always
    		Below 1 Ω
    A61-27 (GND2) - Body ground
    		Always
    		Below 1 Ω
    A61-26 (GND3) - Body ground
    		Always
    		Below 1 Ω
    A61-25 (GND4) - Body ground
    		Always
    		Below 1 Ω
    A61-24 (GND5) - Body ground
    		Always
    		Below 1 Ω
    A61-23 (GND6) - Body ground
    		Always
    		Below 1 Ω

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Skid Control ECU)



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


7.READ VALUE USING INTELLIGENT TESTER (PARKING BRAKE SWITCH)

  1. Reconnect the skid control ECU connector.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Select the Data List on the intelligent tester (Click here).

    ABS/VSC/TRC 
    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 intelligent tester, check if the switch condition on the intelligent tester changes according to parking brake operation.

    OK:
    The intelligent tester displays ON or OFF according to parking brake operation.



NG
Go to step 9
OK


8.INSPECT COMBINATION METER

  1. Turn the power switch off.

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

  1. Check the combination meter.

    OK:
    The brake warning light / red (malfunction) turns on or off in accordance with the intelligent tester operation.


    Result:

    Result
    		Proceed to
    OK (for LHD)
    		A
    OK (for RHD)
    		B
    NG
    		C

    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 part (Click here).



B
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)

C
REPLACE COMBINATION METER (Click here)
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (Click here)  

9.INSPECT PARKING BRAKE SWITCH


    C211519E03

  1. Turn the power 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

    Text in Illustration 
    *a
    		Component without harness connected
    (Parking Brake Switch)

    Result:

    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C



B
REPLACE PARKING BRAKE SWITCH (Click here)

C
REPLACE PARKING BRAKE SWITCH (Click here)
A


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

  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-20 (PKB) - A24-1 (+)
    		Always
    		Below 1 Ω
    2C-20 (PKB) - Body ground
    		Always
    		10 kΩ or higher

    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 part (Click here).



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) (Click here)