C1A4B

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. Based on the signal, the driving support ECU cancels cruise control.





INSPECTION PROCEDURE

HINT
- When this DTC is output, malfunction in the lighting system is suspected. Check if the lighting system is functioning normally How To Proceed With Troubleshooting.
- 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. CHECK DTC OUTPUT (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)

(a) Check DTC for 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) Check for DTCs.

OK:

DTC C1A4B is not output.

NG -- REPLACE DRIVING SUPPORT ECU Removal

OK -- END