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Home >> Toyota >> 2013 >> Prius Two >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Cruise Control Systems >> Dynamic Radar Cruise Control System (Diagnostic Codes & Circuit Tests) (Except Plug-In) >> Dynamic Radar Cruise Control System >> DTC C1A4A: Skid Control Buzzer Circuit >> Procedure
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DTC C1A4A: Skid Control Buzzer Circuit: Procedure

  1. PERFORM ACTIVE TEST USING TECHSTREAM (SKID CONTROL BUZZER) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test / Buzzer.
    5. Perform the Active Test.

      OK

      Skid control buzzer sounds.

    NG → See step   8 

    OK: Go to next step 

  2. CHECK WHETHER DTC OUTPUT RECURS (DTC C1A4A) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    4. Perform the following to make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the malfunction cannot be detected.

      1. Drive the vehicle at a speed for which cruise control operation is possible.
      2. Turn the cruise control main switch on.
      3. Push the -SET switch to activate the cruise control.
    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
    6. Read the DTCs.

      Result

      Result Proceed to
      DTC is not output A
      DTC C1A4A is output B

    B → See step   3 

    A → See step   9 

  3. REPLACE DRIVING SUPPORT ECU 
    1. Replace the driving support ECU. Refer to REMOVAL .

    NEXT: Go to next step 

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC C1A4A) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    4. Perform the following to make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the malfunction cannot be detected.

      1. Drive the vehicle at a speed for which cruise control operation is possible.
      2. Turn the cruise control main switch on.
      3. Push the -SET switch to activate the cruise control.
    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
    6. Read the DTCs.

      Result

      Result Proceed to
      DTC is not output A
      DTC C1A4A is output B

    B → See step   5 

    A → END 

  5. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER 
    1. Replace the brake booster with master cylinder (skid control ECU). Refer to REMOVAL .

    NEXT: Go to next step 

  6. CHECK WHETHER DTC OUTPUT RECURS (DTC C1A4A) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    4. Perform the following to make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the malfunction cannot be detected.

      1. Drive the vehicle at a speed for which cruise control operation is possible.
      2. Turn the cruise control main switch on.
      3. Push the -SET switch to activate the cruise control.
    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
    6. Read the DTCs.

      Result

      Result Proceed to
      DTC is not output A
      DTC C1A4A is output B

    B → See step   7 

    A → END 

  7. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL 
  8. GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
  9. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
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