Stay Alert: Understanding Forward Emergency Braking Warning Light

Tim Miller
Forward Emergency Braking System Light


Your car’s forward emergency braking (FEB) system malfunctions.

Forward Emergency Braking System Light


  • Blocked/Damaged Radar Sensor
  • Interference in Radar Sensor
  • Wiring Issues



Easy to fix


What Is Forward Emergency Braking System?

Forward Emergency Braking (FEB) system, now known as Automatic Emergency Braking (AEB) system, is a safety feature that assists you in preventing the risk of a forward collision. In some car makes, it is also called Collision Mitigation Braking or Forward Collision-Avoidance Assist.

The system uses a radar sensor to detect objects or vehicles in front of your vehicle.

The FEB system works when you drive at speeds above 3 mph. In the event of an imminent collision, the FEB system will provide a warning to the driver, such as an audible alert or visual display on the dashboard. 

If the driver fails to respond to the warning, the system will automatically apply the brakes to slow down or stop the vehicle.

What Does the Forward Emergency Braking System Warning Light Mean?

forward emergency braking system warning light
The forward emergency braking system warning light looks like two cars crashing.

When you turn the ignition on, the FEB system performs a self-test, triggering the light to come on. The light then goes off once the engine is started.

Also, if you have turned the FEB system off on the vehicle information display, the warning light will illuminate to remind you that the system is disabled.

However, when the system is on but the warning light flashes, it indicates that the system has malfunctioned. In this case, you should have your car inspected to identify and resolve any issues.

Why Is the Forward Emergency Braking System Warning Light Always On?

The following are some common causes of the flashing FEB warning light.

1. Blocked or Malfunctioning Radar Sensor
If the radar sensor becomes dirty or obstructed, the FEB system will be disabled and trigger the warning light. You also hear a chime or see a warning message “Unavailable: Front Radar Obstruction” in your vehicle information display.

To resolve this issue, you should pull over to a safe spot, shift to the park (P) position, and turn off the engine. Then clean the sensor area on the front bumper and restart the engine to restore the system.

In case the warning light remains illuminated, the cause may be due to a faulty radar sensor. All you need to do is inspect and replace the sensor.

Sometimes the radar sensor can’t distinguish objects ahead, especially while driving on long bridges, in deserts, or snow fields. Don’t worry as the system is temporarily unavailable. When you cross these areas, turn the system back on.

2. Interference in Radar Sensor
Another potential cause of the FEB warning light is interference in the sensor caused by radar sources like radar-based systems in other vehicles, weather radar systems, or personal radar devices.

In this case, the FEB system will automatically turn off and trigger the warning light to come on. Once the interference clears, the system should turn back on.

3. Wiring Issues
Wiring issues in the FEB system can prevent the sensor from sending accurate information to the ECU. As a result, the system malfunctions and turn the warning light on.

These issues can be caused by wear and tear, corrosion, or damage. It’s crucial to have the vehicle inspected by a qualified mechanic to identify and repair the issue, ensuring the system functions properly.

How to Reset the Forward Emergency Braking System Warning Light

You can quickly turn on/off the FEB warning light by setting on the vehicle information display. Here’s how you can do that:

how to turn the forward emergency braking system on or off
  • Go to “Settings” of the vehicle information display.
  • Select “Driver Assistance” → “Driving Aids” → “Emergency Brake”
  • Select the “Front” option to reset the system. 

Note: When the engine restarts, the AEB system automatically turns on.


Understanding the Forward Emergency Braking warning light is crucial for your safety on the road. By knowing its common causes and how to fix them, you can ensure your FEB system is functioning properly.

Learn more:

Why Is My Brake Light On? 6 Causes & Fixes

5 Reasons Why Your ABS Light Is On (What to Do!!!)

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Information sourced from the owner's manual.