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 brake booster with master cylinder (skid control ECU) to sound the skid control buzzer.

When the brake booster with master cylinder (skid control ECU) detects a malfunction in the VSC warning buzzer circuit, a malfunction signal is sent to the driving support ECU assembly, and this DTC is stored. Although the brake booster with master cylinder (skid control ECU) sends a malfunction signal to the driving support ECU assembly, the vehicle stability control system does not store a relevant malfunction detection DTC.

DTC No. DTC Detection Condition Trouble Area
C1A4A While the power switch is on (IG), a skid control buzzer circuit malfunction signal is received from the brake booster with master cylinder (skid control ECU) for 1 second or more.

  • Skid control buzzer circuit

  • Brake booster with master cylinder (skid control ECU)

  • Driving support ECU assembly

INSPECTION PROCEDURE

Tech Tips

This circuit uses CAN communication. Therefore, be sure to check that the CAN communication system is normal before performing inspection.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (DSS SIGNAL BUZZER)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test / DSS Signal Buzzer.

    5. Check that the skid control buzzer sounds.

      ABS/VSC/TRC
      GTS Display Test Part Control Range Diagnostic Note
      DSS Signal Buzzer Skid control buzzer ON/OFF -
      OK
      Skid control buzzer sounds.

    NG

    GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM Click here

    OK

  2. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (SKID CONTROL ECU)


    1. Replace the brake booster with master cylinder (skid control ECU) Click here (for LHD), Click here (for RHD)).


    NEXT

  3. CHECK DTC OUTPUT (PRE-CRASH SAFETY SYSTEM)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Pre-Crash 2 / Trouble Codes.

    5. Clear the DTCs Click here.

    6. Recheck for DTCs.

      OK
      DTC C1A4A is not output.

    NG

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    OK

    END (BRAKE BOOSTER WITH MASTER CYLINDER (SKID CONTROL ECU) WAS DEFECTIVE)