C1A4B

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

DESCRIPTION

The stop light switch assembly outputs a brake pedal operation signal to the driving support ECU. Based on the signal, the driving support ECU cancels cruise control.





INSPECTION PROCEDURE

NOTICE:
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.

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. CHECK FOR DTC (VEHICLE STABILITY CONTROL SYSTEM)

(a) Check DTCs for the vehicle stability control system Reading and Clearing Diagnostic Trouble Codes.

OK:

Vehicle stability control system DTC is not output.

NG -- GO TO VEHICLE STABILITY CONTROL SYSTEM Vehicle Stability Control System
OK -- Continue to next step.

2. REPLACE BRAKE ACTUATOR (SKID CONTROL ECU)

(a) Replace the brake actuator (skid control ECU) Removal.

NEXT -- Continue to next step.

3. CHECK FOR DTC (PRE-COLLISION 2 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 Pre-Collision System.

OK:

DTC U1A4B is not output.

NG -- REPLACE DRIVING SUPPORT ECU Removal

OK -- END