ELECTRONICALLY CONTROLLED BRAKE SYSTEM ABS Warning Light Remains ON

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:


Tech Tips

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

WIRING DIAGRAM

A01J8NQE02

INSPECTION PROCEDURE

Note

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

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 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)


    1. A01JBTQE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      Disconnect the skid control ECU connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A58-16 (IG1) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)

    OK

  5. INSPECT SKID CONTROL ECU (GND TERMINAL)


    1. A01JBTQE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      Turn the power switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-28 (GND) - Body ground Always Below 1 Ω
      A58-27 (GND2) - Body ground Always Below 1 Ω
      A58-26 (GND3) - Body ground Always Below 1 Ω
      A58-25 (GND4) - Body ground Always Below 1 Ω
      A58-24 (GND5) - Body ground Always Below 1 Ω
      A58-23 (GND6) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

  6. INSPECT COMBINATION METER


    1. Reconnect the skid control ECU connector.

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

    3. 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

      Tech Tips

      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 NO. 3 METER CIRCUIT PLATE Click here

    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here