ELECTRONICALLY CONTROLLED BRAKE SYSTEM ABS does not Operate

DESCRIPTION

When the electronically controlled brake system is operating, as the input piston and output piston are not directly connected, the kickback of the brake pedal is minimal during ABS operation and the driver may not notice that ABS operated.

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU assembly, perform initialization and calibration of the linear solenoid valve.

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PROCEDURE


  1. BRAKE PROBLEM CHECK


    1. Check if the slip indicator light was illuminated or blinking when ABS did not operate.

      Tech Tips


      • When the VSC system is normal and ABS is operating, the slip indicator light blinks.

      • When the VSC system is malfunctioning, the slip indicator light illuminates.

      Result
      Result Proceed to
      The slip indicator light was blinking. A
      The slip indicator light was illuminated. B

    A

    END

    B

  2. CHECK DTC AND FREEZE FRAME DATA


    1. Using the GTS, check DTCs and Freeze Frame Data.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  3. PERFORM OPERATION CHECK DRIVING


    1. Check that ABS operates using a drum tester or equivalent.

      CAUTION:

      To prevent the vehicle from moving unexpectedly out of the tester due to TRC or VSC operation when a drum tester is used, perform the check with TRC and VSC operation prohibited.

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      OK
      ABS operates.
      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here