PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

The millimeter wave radar sensor assembly is connected to the forward recognition camera via CAN communication.

The millimeter wave radar sensor assembly operates the pre-crash alarm by sending a buzzer request signal to the skid control buzzer.

If the millimeter wave radar sensor assembly detects a malfunction in the skid control buzzer circuit, it stores DTC C1A4A.

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

When the ignition switch to ON and the pre-crash alarm is operating, either of the following conditions is met:


  • A buzzer request signal is sent to the skid control buzzer but the buzzer does not sound for 0.3 seconds or more.

  • A buzzer request signal is not sent to the skid control buzzer but the buzzer sounds for 0.3 seconds or more.

  • Skid control buzzer

  • Forward recognition camera

  • Millimeter wave radar sensor assembly

  • Wire harness or connector

WIRING DIAGRAM

B0026CAE01

CAUTION / NOTICE / HINT

Note


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

  • When replacing the millimeter wave radar sensor assembly, always replace it with a new one.

  • When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

    Click here

  • If the forward recognition camera has been replaced with a new one, be sure to perform Forward Recognition Axis Adjustment.

    Click here

  • When a malfunction occurs in the communication line to the forward recognition camera, U023A and/or U1002 is output. If a DTC related to the CAN communication line is output, first troubleshoot the CAN communication line.

    Click here

PROCEDURE


  1. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Crash 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-Crash 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

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

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Crash 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. B0026H2C02
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer)

      Disconnect the G129 skid control buzzer connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G129-2 (IG1) - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

    3. Connect the G129 skid control buzzer connector.

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  3. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER - FORWARD RECOGNITION CAMERA)


    1. Disconnect the G129 skid control buzzer connector.

    2. Disconnect the Q4 forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G129-1 (BZ) - Q4-8 (BZ) Always Below 1 Ω
      G129-1 (BZ) or Q4-8 (BZ) - Body ground Always 10 kΩ or higher

    4. Connect the Q4 forward recognition camera connector.

    5. Connect the G129 skid control buzzer connector.

      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 6 Click here

    NG

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER - FORWARD RECOGNITION CAMERA)


    1. Repair or replace the harness or connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Crash 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-Crash 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Crash 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 (CONFIRM BUZZER OPERATION)


    1. Turn the ignition switch to ON.

    2. Check if the skid control buzzer is sounding.

      Result
      Result Proceed to
      The skid control buzzer does not sound when the ignition switch to ON A
      The skid control buzzer sounds continuously when the ignition switch to ON B

    B

    GO TO STEP 8 Click here

    A

  7. INSPECT SKID CONTROL BUZZER (UNIT INSPECTION)


    1. Remove the skid control buzzer.

      for LHD: Click here

      for RHD: Click here

    2. Inspect the skid control buzzer.

      for LHD: Click here

      for RHD: Click here

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

    B

    GO TO STEP 9 Click here

    A

  8. REPLACE SKID CONTROL BUZZER


    1. Replace the skid control buzzer.

      for LHD: Click here

      for RHD: Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Crash 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-Crash 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

    3. Check for DTCs.

      Click here


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

    A

    END

    B

  10. REPLACE FORWARD RECOGNITION CAMERA


    1. Replace the forward recognition camera.

      Click here

    2. Perform Forward Recognition Axis Adjustment.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Crash 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-Crash 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

    3. Check for DTCs.

      Click here


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

    A

    END (FORWARD RECOGNITION CAMERA WAS DEFECTIVE)

    B

  12. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly.

      Click here

    2. Adjust the millimeter wave radar sensor assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  13. CLEAR DTC (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Crash 2 > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)