DTC    C1A4A    Skid Control Buzzer Circuit

for Preparation Click here


DESCRIPTION

Based on pre-crash control, the driving support ECU communicates to the driver to be careful. The driving support ECU performs this by sending a sounding 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, and this DTC is stored. Although the brake booster with master cylinder (skid control ECU) sends a malfunction signal to the driving support ECU, the vehicle stability control system does not store a relevant malfunction detection DTC.

DTC No.
DTC Detection Condition
Trouble Area
C1A4A
When 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).
  1. Skid control buzzer
  2. Skid control buzzer circuit
  3. Brake booster with master cylinder (skid control ECU)
  4. Driving support ECU

INSPECTION PROCEDURE

HINT:
This circuit uses CAN communication. Therefore, be sure to check that the CAN communication system is normal before performing inspection (Click here).

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SKID CONTROL BUZZER)

  1. Select the Active Test, use the intelligent tester to generate a control command, then check that the skid control buzzer sounds (Click here).

    Chassis / ABS/VSC/TRC 
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Buzzer
    		Skid control buzzer sounds
    		ON/OFF
    		-

    OK:
    Skid control buzzer sounds.



NG
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM (Click here)
OK


2.REPLACE BRAKE BOOSTER WITH MASTER CYLINDER

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

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


NEXT


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

  1. Using the intelligent tester, enter the following menus: Body / Pre-Crash 2 / DTC.

  1. Clear the DTCs (Click here).

  1. Recheck for DTCs.

    OK:
    DTC C1A4A is not output.



NG
REPLACE DRIVING SUPPORT ECU (Click here)
OK

END (SKID CONTROL ECU ASSEMBLY WAS DEFECTIVE)