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DTC C1A4A: Skid Control Buzzer Circuit [10/2014 - 09/2017]: Procedure

  1. CHECK FOR DTCs 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 09/2017]

      Body Electrical > Pre-Collision 2 > Clear DTCs 

    2. Make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 09/2017]

      Body Electrical > Pre-Collision 2 > Trouble Codes 

      Result

      Result Proceed to
      DTC C1A4A, U1002, U0235 and U1104 are not output A
      DTC C1A4A is output B
      DTC C1A4A and U0235 are output C
      DTC C1A4A and U1002 are output D
      DTC C1A4A and U1104 are output E

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017] 

    Result: 

    C 

    GO TO DTC U0235. Refer to  DTC U0235: Lost Communication with Cruise Control Front Distance Range Sensor; DTC U1002: Lost Communication with Gateway Module; DTC U1104: Lost Communication with Driving Support ECU [10/2014 - 09/2017]  

    Result: 

    D 

    GO TO DTC U1002. Refer to  DTC U0235: Lost Communication with Cruise Control Front Distance Range Sensor; DTC U1002: Lost Communication with Gateway Module; DTC U1104: Lost Communication with Driving Support ECU [10/2014 - 09/2017]  

    Result: 

    E 

    GO TO DTC U1104. Refer to  DTC U0235: Lost Communication with Cruise Control Front Distance Range Sensor; DTC U1002: Lost Communication with Gateway Module; DTC U1104: Lost Communication with Driving Support ECU [10/2014 - 09/2017]  

    Result: 

    B 

    See step  2

  2. PERFORM ACTIVE TEST USING TECHSTREAM (SKID CONTROL BUZZER) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Pre-Collision 2 / Active Test.
    5. Perform "Active Test" according to the display on Techstream.

      Body Electrical > Pre-Collision 2 > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON or OFF Buzzer can be heard
      PCS Approach Alarm Buzzer Skid control buzzer ON or OFF Buzzer can be heard

      Body Electrical > Pre-Collision 2 > Active Test 

      Tester Display
      PCS Crash Alarm Buzzer

      Body Electrical > Pre-Collision 2 > Active Test 

      Tester Display
      PCS Approach Alarm Buzzer

      OK

      Skid control buzzer sounds.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - 09/2017] 

    Result: 

    NG 

    See step  3

  3. INSPECT SKID CONTROL BUZZER 
    1. Remove the skid control buzzer.

      Refer to REMOVAL [10/2014 - ]

    2. Inspect the skid control buzzer.

      Refer to INSPECTION [10/2014 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE SKID CONTROL BUZZER. Refer to  REMOVAL [10/2014 - ] 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER - BATTERY) 
    1. Disconnect the skid control buzzer connector.
      GTY511577Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Skid Control Buzzer)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      I36-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      I36-2 (IG1) - Body ground Engine switch off Below 1 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the I36 skid control buzzer connector.
    2. Disconnect the A21 millimeter wave radar sensor assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I36-1 (BZ) - A21-10 (BZ) Always Below 1 Ω
      I36-1 (BZ) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY 
    1. Replace the millimeter wave radar sensor assembly with a new one.

      Refer to REMOVAL [10/2014 - 09/2017]

    2. Perform millimeter wave radar sensor assembly adjustment.

      Refer to ADJUSTMENT [10/2014 - 09/2017]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  7

  7. CHECK FOR DTCs 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 09/2017]

      Body Electrical > Pre-Collision 2 > Clear DTCs 

    2. Make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2014 - 09/2017]

      Body Electrical > Pre-Collision 2 > Trouble Codes 

      Result

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

    Result: 

    A 

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE) 

    Result: 

    B 

    REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [10/2014 - 09/2017] 

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