ANTI-LOCK BRAKE SYSTEM Vacuum Warning Buzzer Circuit

DESCRIPTION

The vacuum warning buzzer (combination meter assembly) sounds repeatedly to warn the driver that the vacuum pressure is insufficient to boost braking force.

WIRING DIAGRAM

Refer to Brake Warning Light Remains ON Click here.

INSPECTION PROCEDURE

Note

The following inspections are performed with the parking brake released. Park the vehicle on a level surface and use chocks to secure the vehicle.

PROCEDURE


  1. CHECK VACUUM WARNING BUZZER


    1. With the engine stopped, depress the brake pedal several times to release the vacuum from the booster and vacuum reservoir tank.

    2. Depress the brake pedal and release the parking brake.

    3. Turn the ignition switch to on (do not start the engine) and confirm that the vacuum warning buzzer (combination meter assembly) sounds.

    4. Start the engine to generate negative pressure, and confirm that the vacuum warning buzzer (combination meter assembly) stops sounding.

      Result
      Result Proceed to
      The vacuum warning buzzer (combination meter assembly) sounds when the ignition switch turned to ON, and a short time after the engine is started, the vacuum warning buzzer (combination meter assembly) stops sounding. A
      The vacuum warning buzzer (combination meter assembly) does not sound, or does not stop sounding. B

    B

    Click here

    A

    END

  2. CHECK VACUUM HOSE


    1. Turn the ignition switch off.

    2. Check the vacuum hose.

      OK
      No cracks or damage on the vacuum hoses.

    NG

    REPLACE VACUUM HOSE

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Disconnect the vacuum warning switch assembly connector.

    2. A01CI3SE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Vacuum Warning Switch Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      V10-1 - Body ground

      Ignition switch ON

      Parking brake switch off

      		 20 to 28 V

    3. Reconnect the vacuum warning switch assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  4. REPLACE VACUUM WARNING SWITCH ASSEMBLY


    1. Replace the vacuum warning switch assembly Click here.


    NEXT

  5. CHECK VACUUM WARNING BUZZER


    1. With the engine stopped, depress the brake pedal several times to release the vacuum from the booster and vacuum reservoir tank.

    2. Depress the brake pedal and release the parking brake.

    3. Turn the ignition switch to on (do not start the engine) and confirm that the vacuum warning buzzer (combination meter assembly) sounds.

    4. Start the engine to generate negative pressure, and confirm that the vacuum warning buzzer (combination meter assembly) stops sounding.

      Result
      Result Proceed to
      The vacuum warning buzzer (combination meter assembly) sounds when the ignition switch turned to ON, and a short time after the engine is started, the vacuum warning buzzer (combination meter assembly) stops sounding. A
      The vacuum warning buzzer (combination meter assembly) does not sound, or does not stop sounding. B

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    END