Pre-Collision System

PRE-COLLISION: PRE-COLLISION SYSTEM: C1A4B: Stop Light Relay Circuit
C1A4B - Stop Light Relay Circuit

DESCRIPTION

The stop light switch assembly sends a brake pedal operation signal to the driving support ECU assembly. Based on the signal, the driving support ECU assembly detects the operation of the brake pedal.





INSPECTION PROCEDURE

NOTICE:
When this DTC is output, malfunction in the electronically controlled brake system is suspected. Check if the electronically controlled brake system is functioning normally How To Proceed With Troubleshooting.

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

PROCEDURE

1. CHECK DTC OUTPUT (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)

(a) Check DTCs for the electronically controlled brake system Reading and Clearing Diagnostic Trouble Codes.

OK:

Electronically controlled brake system DTC is not output.

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 C1A4B is not output.

NG -- REPLACE DRIVING SUPPORT ECU ASSEMBLY Removal

OK -- END (BRAKE BOOSTER WITH MASTER CYLINDER WAS DEFECTIVE)