EBD Warning Light (Brake Warning Light) Comes ON Steady

EBD Warning Light (Brake Warning Light) Comes ON Steady

Wiring Diagram

Referring to "Wiring Diagram" under ABS Warning Light Does Not Come ON at Ignition Switch ON ABS Warning Light Does Not Come ON at Ignition Switch ON.

Circuit Description

EBD warning light (brake warning light) is controlled by ABS control module and BCM through light driver module in combination meter.

If EBD system is in good condition, ABS control module turns EBD warning light ON at the ignition switch ON, keeps it ON for 2 seconds and then turns it OFF.

EBD warning light is turned ON continuously at the following conditions.

- EBD system is an abnormality
- Connector of ABS control module is disconnected
- Parking brake switch is ON
- Brake fluid level is lower than minimum level

The information of parking brake switch and brake fluid level are transmitted from BCM to light driver module in combination meter through CAN communication line.

Troubleshooting



1. Parking brake and brake fluid level check

Make sure that:
- Parking brake is completely released.
- Brake fluid level is upper than the minimum level.

Are the check results OK?
YES
Go to Step 2.
NO
Release parking brake completely and/or replenish brake fluid.

2. ABS warning light operation check

Turn ignition switch to ON position.

Does ABS warning light come on steady?
YES
Perform ABS Warning Light Comes ON Steady
previously outlined.
NO
Go to Step 3.

3. Parking brake switch circuit and brake fluid level switch circuit check

Release parking brake completely, and replenish brake fluid.
Disconnect BCM connectors with ignition switch turned OFF.
Measure resistance between each parking brake switch circuit, brake fluid level switch circuit.

Are resistance infinity ohms?
YES
Go to Step 4.
NO
Check each applicable circuit for short to vehicle body ground. If OK then check parking brake switch and/or brake fluid level switch.

4. DTC check of BCM

Connect scan tool to DLC with ignition switch turned OFF.
Turn ignition switch to ON position and check DTC of BCM.

Is there DTC U0073?
YES
Go to DTC U0073 (No. 0073): Control Module Communication Bus Off.
NO
Go to Step 5.

5. CAN communication line circuit check

Turn ignition switch to OFF position.
Disconnect connectors of all control modules communicating by means of CAN.
Check for proper connection to CAN communication line wire.
If OK then check CAN communication line circuit between control modules for open, short and high resistance.

Is each CAN communication line circuit in good condition?
YES
Substitute a known-good combination meter and recheck. If EBD warning light remains OFF, substitute a known-good BCM and/or ABS hydraulic unit / control module assembly and recheck.
NO
Repair CAN communication line circuit.