PRE-COLLISION SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

The driving support ECU assembly operates the pre-collision warning by sending a buzzer request signal to the skid control buzzer assembly.

If the driving support ECU assembly detects a malfunction in the skid control buzzer assembly circuit, it will store DTC C1A4A.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1A4A Skid Control Buzzer Circuit

When the engine switch is on (IG) and the pre-collision warning is operating, either of the following conditions is met:


  • A buzzer request signal is sent to the skid control buzzer assembly but the buzzer does not sound for 1 second or more.

  • A buzzer request signal is not sent to the skid control buzzer assembly but the buzzer sounds for 1 second or more.

  • Skid control buzzer assembly

  • Driving support ECU assembly

  • Wire harness or connector

WIRING DIAGRAM

B0077RXE23
*a from IG1 NO. 3 Relay
*b IG1 NO. 3
*c Skid Control Buzzer Assembly
*d Driving Support ECU Assembly

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.

PROCEDURE


  1. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

    2. Perform the Active Test according to the display on the GTS.

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Skid control buzzer assembly ON / OFF Test possible with engine switch on (IG), vehicle stopped

      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display
      PCS Collision Alarm Buzzer

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Trouble Codes
      Result
      Result Proceed to
      DTC C1A4A is not output A
      DTC C1A4A is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

  2. CHECK TERMINAL VOLTAGE


    1. B0074BSC38
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

      Disconnect the O40 skid control buzzer assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      O40-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V

    3. Connect the O40 skid control buzzer assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - BATTERY)

    OK

  3. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)


    1. Disconnect the O40 skid control buzzer assembly connector.

    2. Disconnect the Q2 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      O40-1 (BZ) - Q2-3 (BZ) Always Below 1 Ω
      O40-1 (BZ) or Q2-3 (BZ) - Body ground Always 10 kΩ or higher

    4. Connect the Q2 driving support ECU assembly connector.

    5. Connect the O40 skid control buzzer assembly connector.

      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 6 Click here

    NG

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)


    1. Repair or replace the harness or connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

    2. Perform the Active Test according to the display on the GTS.

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Skid control buzzer assembly ON / OFF Test possible with engine switch on (IG), vehicle stopped

      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display
      PCS Collision Alarm Buzzer

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Trouble Codes
      Result
      Result Proceed to
      DTC C1A4A is not output A
      DTC C1A4A is output B

    A

    END

    B

  6. INSPECT SKID CONTROL BUZZER ASSEMBLY (CONFIRM BUZZER OPERATION)


    1. Turn the engine switch on (IG).

    2. Check if the skid control buzzer assembly is sounding.

      Result
      Result Proceed to
      The skid control buzzer assembly does not sound when the engine switch is on (IG) A
      The skid control buzzer assembly sounds continuously when the engine switch is on (IG) B

    B

    GO TO STEP 8 Click here

    A

  7. INSPECT SKID CONTROL BUZZER ASSEMBLY (UNIT INSPECTION)


    1. Remove the skid control buzzer assembly.

      Click here

    2. Inspect the skid control buzzer assembly.

      Click here

      Result
      Result Proceed to
      Skid control buzzer assembly is abnormal A
      Skid control buzzer assembly is normal B

    B

    GO TO STEP 9 Click here

    A

  8. REPLACE SKID CONTROL BUZZER ASSEMBLY


    1. Replace the skid control buzzer assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

    2. Perform the Active Test according to the display on the GTS.

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Skid control buzzer assembly ON / OFF Test possible with engine switch on (IG), vehicle stopped

      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display
      PCS Collision Alarm Buzzer

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Trouble Codes
      Result
      Result Proceed to
      DTC C1A4A is not output A
      DTC C1A4A is output B

    A

    END

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here