ELECTRONICALLY CONTROLLED BRAKE SYSTEM > ABS 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 ABS warning light remains on:
  1. The skid control ECU connector is 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 the skid control ECU.
  4. The ABS control system is defective.

HINT:
In some cases, the intelligent tester cannot be used when the skid control ECU is malfunctioning.


WIRING DIAGRAM


C209415E06


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 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 AUXILIARY BATTERY

  1. Check the auxiliary battery voltage.

    Standard Voltage:
    11 to 14 V



NG
CHARGE OR REPLACE AUXILIARY BATTERY
OK


4.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


5.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


6.INSPECT COMBINATION METER

  1. Reconnect the skid control ECU connector.

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

  1. Check the combination meter.

    OK:
    The ABS warning light 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)