Pre-Collision System

PRE-COLLISION: PRE-COLLISION SYSTEM: C1A4A: Skid Control Buzzer Circuit
C1A4A - Skid Control Buzzer Circuit

DESCRIPTION

Based on pre-collision 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 DTC C1A4A 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.





INSPECTION PROCEDURE

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

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (SKID CONTROL BUZZER)

(a) Select the Active Test, use the Techstream to generate a control command, then check that the skid control buzzer sounds Data List / Active Test.

Chassis/ABS/VSC/TRAC





OK:

Skid control buzzer sounds.

NG -- GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM Electronically Controlled Brake System
OK -- Continue to next step.

2. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER

(a) Replace the brake booster with master cylinder (skid control ECU) Removal.

NEXT -- Continue to next step.

3. CHECK DTC OUTPUT (PRE-COLLISION SYSTEM)

(a) Using the Techstream, enter the following menus: Body Electrical / Pre-Collision 2 / Trouble Codes.

(b) Clear the DTCs Pre-Collision System.

(c) Recheck for DTCs.

OK:

DTC C1A4A is not output.

NG -- REPLACE DRIVING SUPPORT ECU Removal

OK -- END