PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

Based on pre-crash control, the driving support ECU assembly provides warnings to the driver. The driving support ECU assembly does this by sending a request signal to the millimeter wave radar sensor assembly to sound the skid control buzzer.

When the millimeter wave radar sensor assembly detects a malfunction in the skid control buzzer circuit, a malfunction signal is sent to the driving support ECU assembly, and this DTC is stored.

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

While the ignition switch is ON, and the pre-crash alarm control 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 1 second or more.

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

  • Harness or connector

  • Skid control buzzer

  • Driving support ECU assembly

WIRING DIAGRAM

A01VAL1E02

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 DTC


    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

      Tech Tips

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


      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 ON, 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
      OK
      DTC C1A4A is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER - BATTERY)


    1. A01VAXTC80
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer)

      Disconnect the skid control buzzer connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G74-2 (IG1) - Body ground Ignition switch ON

      11 to 14 V*1

      9.5 to 14 V*2
      G74-2 (IG1) - Body ground Ignition switch off Below 1 V
      *1: w/o Stop and Start System
      *2: w/ Stop and Start System
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the G74 skid control buzzer connector.

    2. Disconnect the G168 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
      G74-1 (BZ) - G168-3 (BZ) Always Below 1 Ω
      G74-1 (BZ) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 6 Click here

    NG

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace harness or connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTC


    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

      Tech Tips

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


      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 ON, 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
      OK
      DTC C1A4A is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (HARNESS OR CONNECTOR WAS DEFECTIVE)

    NG

  6. INSPECT SKID CONTROL BUZZER (CONFIRM BUZZER OPERATION)


    1. Turn the ignition switch to ON.

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

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

    B

    GO TO STEP 8 Click here

    A

  7. INSPECT SKID CONTROL BUZZER (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


    1. Replace the skid control buzzer assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR DTCs


    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 assembly ON / OFF Test possible with ignition switch to ON, 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 (SKID CONTROL BUZZER WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY for LHD: Click here
    REPLACE DRIVING SUPPORT ECU ASSEMBLY for RHD: Click here