ELECTRONICALLY CONTROLLED BRAKE SYSTEM Abnormal Noise is Heard from the Engine Compartment when Depressing the Brake Pedal

DESCRIPTION

Troubleshooting for when abnormal sound occurs from the engine compartment due to air when the brake pedal is depressed.

CAUTION / NOTICE / HINT

Note

After replacing the brake booster with master cylinder assembly, perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

Click here

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the power switch off.

    3. Turn the power switch on (IG).

    4. Check the DTCs that are output.

      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

  2. PERFORM AIR BLEEDING


    1. Perform the air bleeding procedure in Bleed Brake System.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  3. RECHECK SYMPTOM


    1. Depress the brake pedal and check if the symptom disappeared.

      Result
      Result Proceed to
      The symptom disappeared (abnormal sound does not occur). A
      The symptom does not disappear (abnormal sound occurs). B

    B

    PERFORM FORCED ACTUATOR REFRESH Click here

    A

  4. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

    END

  5. PERFORM FORCED ACTUATOR REFRESH


    1. Check that the following conditions required to perform "forced actuator refresh" are met and perform "forced actuator refresh" using the GTS.


      1. The shift state indicator shows that the vehicle shift state is park (P).

      2. The parking brake is applied.

      3. Vehicle speed is 0 km/h (0 mph).

      4. The brake pedal is not depressed.

      5. The READY light in the combination meter assembly is illuminated (or the power switch is on (IG) while the auxiliary battery is being backed up with a power supply).


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      Forced Actuator Refresh

      Note

      As brake fluid pressure is being generated while performing "forced actuator refresh", do not depress the brake pedal or perform a brake system related procedure.

      Tech Tips

      While performing "forced actuator refresh", the accumulator pressure may decrease and the meter buzzer may sound.

    2. After "forced actuator refresh" has completed, check the time taken to perform the "forced actuator refresh" displayed on the GTS.

      OK
      The time taken to perform "forced actuator refresh" is 10 minutes and 50 seconds or more.
      Result
      Proceed to
      OK
      NG

      Note

      If the time taken to perform "forced actuator refresh" is less than 10 minutes and 50 seconds, "forced actuator refresh" may have canceled without completing properly. In this case, check the conditions required to perform "forced actuator refresh" are met and perform "forced actuator refresh" again.


    NG

    PERFORM FORCED ACTUATOR REFRESH AGAIN

    OK

  6. RECHECK SYMPTOM


    1. Depress the brake pedal and check if the symptom disappeared.

      Result
      Result Proceed to
      The symptom disappeared (abnormal sound does not occur). A
      The symptom does not disappear (abnormal sound occurs). B

    B

    PERFORM FORCED ACTUATOR REFRESH Click here

    A

  7. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

      Tech Tips

      As DTC C1256 (Accumulator Low Pressure) may be stored by performing "forced actuator refresh", clear the DTCs after performing "forced actuator refresh".

      Result
      Proceed to
      NEXT

    NEXT

    END

  8. PERFORM FORCED ACTUATOR REFRESH


    1. Check that the following conditions required to perform "forced actuator refresh" are met and perform "forced actuator refresh" using the GTS.


      1. The shift state indicator shows that the vehicle shift state is park (P).

      2. The parking brake is applied.

      3. Vehicle speed is 0 km/h (0 mph).

      4. The brake pedal is not depressed.

      5. The READY light in the combination meter assembly is illuminated (or the power switch is on (IG) while the auxiliary battery is being backed up with a power supply).


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      Forced Actuator Refresh

      Note

      As brake fluid pressure is being generated while performing "forced actuator refresh", do not depress the brake pedal or perform a brake system related procedure.

      Tech Tips

      While performing "forced actuator refresh", the accumulator pressure may decrease and the meter buzzer may sound.

    2. After "forced actuator refresh" has completed, check the time taken to perform the "forced actuator refresh" displayed on the GTS.

      OK
      The time taken to perform "forced actuator refresh" is 10 minutes and 50 seconds or more.
      Result
      Proceed to
      OK
      NG

      Note

      If the time taken to perform "forced actuator refresh" is less than 10 minutes and 50 seconds, "forced actuator refresh" may have canceled without completing properly. In this case, check the conditions required to perform "forced actuator refresh" are met and perform "forced actuator refresh" again.


    NG

    PERFORM FORCED ACTUATOR REFRESH AGAIN

    OK

  9. RECHECK SYMPTOM


    1. Depress the brake pedal and check if the symptom disappeared.

      Result
      Result Proceed to
      The symptom disappeared (abnormal sound does not occur). A
      The symptom does not disappear (abnormal sound occurs). B

    B

    PERFORM FORCED ACTUATOR REFRESH Click here

    A

  10. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

      Tech Tips

      As DTC C1256 (Accumulator Low Pressure) may be stored by performing "forced actuator refresh", clear the DTCs after performing "forced actuator refresh".

      Result
      Proceed to
      NEXT

    NEXT

    END

  11. PERFORM FORCED ACTUATOR REFRESH


    1. Check that the following conditions required to perform "forced actuator refresh" are met and perform "forced actuator refresh" using the GTS.


      1. The shift state indicator shows that the vehicle shift state is park (P).

      2. The parking brake is applied.

      3. Vehicle speed is 0 km/h (0 mph).

      4. The brake pedal is not depressed.

      5. The READY light in the combination meter assembly is illuminated (or the power switch is on (IG) while the auxiliary battery is being backed up with a power supply).


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      Forced Actuator Refresh

      Note

      As brake fluid pressure is being generated while performing "forced actuator refresh", do not depress the brake pedal or perform a brake system related procedure.

      Tech Tips

      While performing "forced actuator refresh", the accumulator pressure may decrease and the meter buzzer may sound.

    2. After "forced actuator refresh" has completed, check the time taken to perform the "forced actuator refresh" displayed on the GTS.

      OK
      The time taken to perform "forced actuator refresh" is 10 minutes and 50 seconds or more.
      Result
      Proceed to
      OK
      NG

      Note

      If the time taken to perform "forced actuator refresh" is less than 10 minutes and 50 seconds, "forced actuator refresh" may have canceled without completing properly. In this case, check the conditions required to perform "forced actuator refresh" are met and perform "forced actuator refresh" again.


    NG

    PERFORM FORCED ACTUATOR REFRESH AGAIN

    OK

  12. RECHECK SYMPTOM


    1. Depress the brake pedal and check if the symptom disappeared.

      Result
      Result Proceed to
      The symptom disappeared (abnormal sound does not occur). A
      The symptom does not disappear (abnormal sound occurs). B

      Tech Tips

      If the symptom does not disappear even after "forced actuator refresh" has completed properly 3 times, replace the brake booster with master cylinder assembly.


    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY for LHD: Click here
    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY for RHD: Click here

    A

  13. CLEAR DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

      Tech Tips

      As DTC C1256 (Accumulator Low Pressure) may be stored by performing "forced actuator refresh", clear the DTCs after performing "forced actuator refresh".

      Result
      Proceed to
      NEXT

    NEXT

    END