EBD Warning Light (Brake Warning Light) Comes ON Steady

EBD Warning Light (Brake Warning Light) Comes ON Steady

Circuit Diagram










Circuit Description

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

If EBD system is in good condition, ESP(R) control module turns ON EBD warning light (brake warning light) when engine switch is pressed to change ignition mode of keyless push start system to ON, keeps it ON for 2 seconds and then turns it OFF.

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

- EBD system has an abnormality
- Parking brake lever is pulled up
- Brake fluid level is lower than minimum level

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

Also, it is turned ON continuously by light driver module when the connector of ESP(R) control module is disconnected.

Troubleshooting

1. ESP(R) control module connector check

Check for proper connection to ESP(R) control module connector.

Is it in good condition?
YES -
Go to Step 2.
NO -
Connect connector securely.

2. Parking brake and brake fluid level check

Check the following points.
- Parking brake is completely released.
- Brake fluid level is upper than minimum level. Brake Fluid Level Inspection

Are they in good condition?
YES -
Go to Step 3.
NO -
Release parking brake and check brake fluid level.

3. ABS warning light operation check

Push engine switch to change ignition mode to "ON".

Does "ABS" warning light come ON steady?
YES -
Perform "ABS Warning Light Comes ON Steady".
NO -
Go to Step 4.

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

Confirm that ignition mode of keyless push start system is in "OFF".
Disconnect "E05" and "L03" connectors from BCM.
Check the following points.
- Resistance between "E05-18" and ground: 2 ohms or less
- Resistance between "L03-21" and ground: 2 ohms or less

Are they in good condition?
YES -
Check each applicable circuit for short to ground.
If OK, check parking brake switch and/or brake fluid level switch.
- Parking brake switch: Testing and Inspection
- Brake fluid level switch: Testing and Inspection
NO -
Go to Step 5.

5. CAN communication circuit check

Connect "E05" and "L03" connectors to BCM.
Connect scan tool to DLC.
Push engine switch to change ignition mode to "ON".
Check DTC.

Is DTC U0073 detected?
YES -
Go to "Troubleshooting for Communication Bus Off":.
NO -
Go to Step 6.

6. DTC check for BCM

Connect scan tool to DLC.
Push engine switch to change ignition mode to "ON".
Check DTC for BCM.

Is DTC U0073 detected?
YES -
Go to "Troubleshooting for Communication Bus Off":.
NO -
Substitute a know-good combination meter and recheck DTC. IF "ABS" warning light comes ON steady, substitute a know-good ESP(R) control module. ESP Hydraulic Unit / Control Module Assembly Removal and Installation