ANTI-LOCK BRAKE SYSTEM ABS Warning Light Remains ON

DESCRIPTION

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


  1. The 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 or short in the wire harness between the combination meter and skid control ECU.

WIRING DIAGRAM

A0138OSE01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK FOR DTC


    1. Check if any DTCs are output.

      Result
      Result Proceed to
      DTC not output A
      DTC output B

    B

    REPAIR CIRCUIT INDICATED BY OUTPUT DTCS

    A

  2. CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED


    1. Check if the skid control ECU (brake actuator assembly) connector is securely connected.

      OK
      The connector is securely connected.

    NG

    CONNECT CONNECTOR TO ECU CORRECTLY

    OK

  3. CHECK BATTERY


    1. Check the battery voltage.

      Standard voltage
      11 to 14 V

    NG

    REPAIR OR REPLACE CHARGING SYSTEM OR BATTERY

    OK

  4. CHECK ABS WARNING LIGHT


    1. Turn the ignition switch off.

    2. A0136PEE08
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the skid control ECU (brake actuator assembly) connector.

    3. Ground terminal WA of the skid control ECU (brake actuator assembly).

    4. Turn the ignition switch to ON.

    5. Check the ABS warning light.

      OK
      Condition Illumination Condition
      A46-3 (WA) - Body ground Connected OFF
      A46-3 (WA) - Body ground Disconnected ON

      Tech Tips


      • When the ABS warning light goes out, ground failure or open circuits in the brake actuator should be considered.

      • When the ABS warning light remains illuminated, opens in the wire harness among the combination meters or abnormalities in the meter circuit should be considered.


    NG

    CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER ASSEMBLY) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)


    1. A0136PEE09
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A46-28 (IG1) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR (IG1 CIRCUIT)

    OK

  6. CHECK HARNESS AND CONNECTOR (GND1, GND2 TERMINAL)


    1. A0136PEE10
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-38 (GND1) - Body ground Always Below 1 Ω
      A46-13 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1, GND2 CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER ASSEMBLY)


    1. Turn the ignition switch off.

    2. Disconnect the A46 skid control ECU (brake actuator assembly) connector and the A22 combination meter assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-3 (WA) - A22-16 (LP) Always Below 1 Ω
      A46-3 (WA) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here