ABS Warning Light Remains ON

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

INSPECT BATTERY

CHECK CAN COMMUNICATION LINE

CHECK DTC (CAN COMMUNICATION SYSTEM)

CHECK OPERATION OF ABS WARNING LIGHT (ACTIVE TEST)

INSPECT SKID CONTROL ECU (IG1 TERMINAL)

INSPECT SKID CONTROL ECU (GND TERMINAL)

Description

If any of the following is detected, the ABS warning light remains on.

  1. The skid control ECU connectors are disconnected from the skid control ECU.
  2. There is a malfunction in the skid control ECU internal circuit.
  3. There is an open in the harness between the combination meter and skid control ECU.

HINT:

There is a case that the intelligent tester cannot be used when the skid control ECU is abnormal.

Wiring diagram

Land Cruiser. ABS Warning Light Remains ON. Wiring diagram

Inspection procedure

NOTICE:

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

1.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  
   

2.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  
   

3.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  
   

4.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  
   

5.CHECK OPERATION OF ABS 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 ABS warning light by operating the intelligent tester.

    Combination Meter
    Tester Display Test Part Control Range Diagnostic Note
    Indicat. Lamp ABS ABS 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  
   

6.INSPECT SKID CONTROL ECU (IG1 TERMINAL)

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

  1. Disconnect the A24 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
    A24-46 (IG1) - Body ground Ignition switch ON 11 to 14 V
  NG  
REPAIR OR REPLACE HARNESS OR CONNECTOR
 
OK  
   

7.INSPECT SKID CONTROL ECU (GND TERMINAL)

Land Cruiser. ABS Warning Light Remains ON. 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 ?
    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