Brake Warning Light Remains ON

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK DTC

INSPECT IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

INSPECT BATTERY

CHECK CAN COMMUNICATION LINE

CHECK DTC (CAN COMMUNICATION SYSTEM)

CHECK OPERATION OF BRAKE WARNING LIGHT (ACTIVE TEST)

INSPECT SKID CONTROL ECU (IG1 TERMINAL)

INSPECT SKID CONTROL ECU (GND TERMINAL)

INSPECT PARKING BRAKE SWITCH

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - PARKING BRAKE SWITCH)

Description

The BRAKE warning light comes on when brake fluid is insufficient, the parking brake is applied or the EBD is defective.

Wiring diagram

Brake Warning Light Remains ON. Land Cruiser. Wiring diagram

Inspection procedure

NOTICE:

When replacing the master cylinder solenoid, perform zero point calibration .

1.CHECK DTC

  1. Check for DTCs .

    Result
    Result Proceed to
    DTC is not output A
    DTC is output B
  B  
REPAIR CIRCUIT INDICATED BY OUTPUT DTC
 
A  
   

2.INSPECT IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

  1. Check the skid control ECU connector connection.

    OK:

    The connector is securely connected.

  NG  
CONNECT CONNECTOR TO ECU CORRECTLY
 
OK  
   

3.INSPECT BATTERY

  1. Check the battery voltage.

    Standard voltage:

    11 to 14 V

    Result
    Result Proceed to
    OK A
    NG 1GR-FE B
    2UZ-FE C
    1VD-FTV D
  B  
GO TO CHARGING SYSTEM (ON-VEHICLE INSPECTION)
 
  C  
GO TO CHARGING SYSTEM (ON-VEHICLE INSPECTION)
 
  D  
GO TO CHARGING SYSTEM (ON-VEHICLE INSPECTION)
 
A  
   

4.CHECK CAN COMMUNICATION LINE

  1. Turn the ignition switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and the intelligent tester on.

  1. Select "Bus Check" from the System Selection Menu screen, and follow the prompts on the screen to inspect the CAN Bus.

    OK:

    "Bus Check" indicates no malfunctions in CAN communication.

    Result
    Result Proceed to
    OK A
    NG LHD B
    RHD C
  B  
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)
 
  C  
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)
 
A  
   

5.CHECK DTC (CAN COMMUNICATION SYSTEM)

  1. Turn the ignition switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and the intelligent tester on.

  1. Check for DTCs (LHD: /RHD: ).

    Result
    Result Proceed to
    CAN system DTC is not output A
    CAN system DTC is output LHD B
    RHD C
  B  
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)
 
  C  
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)
 
A  
   

6.CHECK OPERATION OF BRAKE WARNING LIGHT (ACTIVE TEST)

  1. Turn the ignition switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and the intelligent tester on.

  1. Enter the following menus: Body Electrical / Combination Meter / Active Test.

  1. Check the condition of the brake warning light by operating the intelligent tester.

    Combination Meter
    Tester Display Test Part Control Range Diagnostic Note
    Indicat. Lamp Brake Brake Warning Light Warning light ON/OFF -

    OK:

    The warning light turns on when operating the intelligent tester.

    Result
    Result Proceed to
    OK A
    NG w/ Multi-information Display B
    w/o Multi-information Display C
  B  
REPLACE COMBINATION METER ASSEMBLY
 
  C  
REPLACE COMBINATION METER ASSEMBLY
 
A  
   

7.INSPECT SKID CONTROL ECU (IG1 TERMINAL)

Brake Warning Light Remains ON. Land Cruiser. Disconnect the A24 skid control ECU connector.

  1. Disconnect the A24 skid control ECU connector.

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

    Standard Voltage:

    Tester Connection Switch Condition Specified Condition
    A24-46 (IG1) - Body ground Ignition switch ON 11 to 14 V
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

8.INSPECT SKID CONTROL ECU (GND TERMINAL)

Brake Warning Light Remains ON. Land Cruiser. Disconnect the A24 and A25 skid control ECU connectors.

  1. Disconnect the A24 and A25 skid control ECU connectors.

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

    Standard Resistance:

    Tester Connection Condition Specified Condition
    A24-1 (GND1) - Body ground Always Below 1 ?
    A24-32 (GND2) - Body ground Always Below 1 ?
    A25-4 (GND3) - Body ground Always Below 1 ?
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

9.INSPECT PARKING BRAKE SWITCH

Brake Warning Light Remains ON. Land Cruiser. Disconnect the E53 parking brake switch connector.

  1. Disconnect the E53 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 ?
    1 - Body ground Parking brake switch off (Switch pin pushed in) 10 k? or higher
  NG  
REPLACE PARKING BRAKE SWITCH ASSEMBLY
 
OK  
   

10.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - PARKING BRAKE SWITCH)

Brake Warning Light Remains ON. Land Cruiser. Measure the resistance according to the value(s) in the table below.

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

    Standard Resistance:

    Tester Connection Condition Specified Condition
    A24-28 (PKB) - E53-1 Always Below 1 ?
    A24-28 (PKB) - Body ground Always 10 k? or higher
    Result
    Result Proceed to
    NG A
    OK LHD B
    RHD C
  B  
REPLACE MASTER CYLINDER SOLENOID
 
  C  
REPLACE MASTER CYLINDER SOLENOID
 
A  
   
REPAIR OR REPLACE HARNESS OR CONNECTOR