LEMON Manuals: Even more car manuals for everyone
Home >> Audi >> 2015 >> A4 Prestige >> Repair and Diagnosis >> External Pages >> Different car >> Section 420 (Electronically Controlled Brake System (Diagnostic Codes & Symptom Tests)) >> Electronically Controlled Brake System >> Circuit Tests >> Skid Control Buzzer Circuit [08/2013 - ] >> Procedure

Skid Control Buzzer Circuit [08/2013 - ]: Procedure

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK BUZZER OPERATION 
    1. Confirm problem symptoms of the skid control buzzer assembly according to the customer problem analysis.

      Result

      Result Proceed to
      Buzzer does not sound. A
      Buzzer sounds constantly. B

    B → See step   7 

    A: Go to next step 

  2. PERFORM ACTIVE TEST USING TECHSTREAM (SKID CONTROL BUZZER ASSEMBLY) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Select the Active Test on the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2013 - ] .
      ABS/VSC/TRAC

      Tester Display Test Part Control Range Diagnostic Note
      DSS Signal Buzzer Skid control buzzer assembly Buzzer ON/OFF Buzzer can be heard
    4. Check that the buzzer sounds/stops when turning the skid control buzzer assembly on/off using the Techstream.

      Result

      Result Proceed to
      Buzzer does not sound. A
      Buzzer sounds/stops. B

      HINT: 

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step. Refer to PROBLEM SYMPTOMS TABLE [08/2013 - ] .

    B → See step   12 

    A: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL) 
    1. Turn the power switch off.
      GTY396041Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the H65 skid control buzzer assembly connector.
    3. Turn the power switch on (IG).
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      H65-2 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Skid Control Buzzer Assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    OK: Go to next step 

  4. INSPECT SKID CONTROL BUZZER ASSEMBLY 
    1. Turn the power switch off.
      GTY326073Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect a negative (-) lead from the auxiliary battery to terminal 1 (BZ), and a positive (+) lead to terminal 2 (IG1) of the skid control buzzer assembly, and then check that the buzzer sounds.

      OK

      The skid control buzzer assembly sounds.

      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Skid Control Buzzer Assembly)

    NG → See step   11 

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - SKID CONTROL BUZZER ASSEMBLY) 
    1. Disconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector 2 minutes after the power switch is turned off.

      HINT: 

      Do not open/close the driver door within 2 minutes after the power switch is turned off.

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      A24-13 (BZ) - H65-1 (BZ) Always Below 1 Ω
      A24-13 (BZ) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  6. CHECK HARNESS AND CONNECTOR (GND TERMINAL) 
    1. Measure the resistance according to the value(s) in the table below.
      GTY420132Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      A24-28 (GND) - Body ground Always Below 1 Ω
      A24-27 (GND2) - Body ground Always Below 1 Ω
      A24-26 (GND3) - Body ground Always Below 1 Ω
      A24-25 (GND4) - Body ground Always Below 1 Ω
      A24-24 (GND5) - Body ground Always Below 1 Ω
      A24-23 (GND6) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

      HINT: 

      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. Refer to PROBLEM SYMPTOMS TABLE [08/2013 - ] .

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

    OK → See step   10 

  7. INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY 
    1. Disconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
    2. Check the skid control buzzer assembly operation.

      Result

      Result Proceed to
      Buzzer stops. A
      Buzzer sounds constantly. B

      HINT: 

      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. Refer to PROBLEM SYMPTOMS TABLE [08/2013 - ] .

    B → See step   8 

    A → See step   10 

  8. REPLACE SKID CONTROL BUZZER ASSEMBLY 
    1. Reconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
    2. Replace the skid control buzzer assembly. Refer to REMOVAL [08/2013 - ] .
    3. Check the skid control buzzer assembly operation.

      Result

      Result Proceed to
      Buzzer stops. A
      Buzzer sounds constantly. B

    B → See step   9 

    A → END 

  9. CHECK IF CONNECTOR IS SECURELY CONNECTED 
    1. Gently jiggle the connectors and wire harnesses and check the skid control buzzer assembly operation.

      Result

      Result Proceed to
      Buzzer stops. A
      Buzzer sounds constantly. B

    B → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    A → END 

  10. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [08/2013 - ] 
  11. REPLACE SKID CONTROL BUZZER ASSEMBLY. Refer to  REMOVAL [08/2013 - ] 
  12. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - ]