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    Blind Spot Warning not working properly

    The warning light in the door mirror comes on even though there's no vehicle alongside you, or the system fails to warn you even though someone is in your blind spot. This is often described as a problem with the Blind Spot Warning.

    Blind Spot Warning (BSW) warns the driver when another road user is in the blind spot. The system usually uses radar sensors in the rear bumper for this.

    A false or missing warning doesn't automatically mean the system is faulty. How it behaves depends partly on the traffic situation, the position of the sensors and the conditions.

    Have you experienced a false or missing warning? Report your experience to ADAS Meldpunt. Your report helps show where Blind Spot Warning reacts differently in practice than expected.

    Does this sound familiar? Share your experience with ADAS Meldpunt. Your report helps build a clearer picture of how driver assistance systems perform in everyday driving.

    Report an incident

    What does the Blind Spot Warning do?

    Blind Spot Warning monitors the area beside and just behind the car. When the system detects a vehicle in the blind spot, a warning light usually appears in or near the door mirror. In some vehicles, an additional warning follows if the driver still indicates.

    The precise operation varies by vehicle. Your car's handbook will confirm the detection area and the conditions under which the system works.

    What unexpected behaviour might you experience?

    The points below describe experiences, not diagnoses.

    • the warning light is on even though there's no vehicle in the blind spot;
    • the system doesn't warn you even though there is a vehicle in the blind spot;
    • the warning comes too late, for example only once an overtaking vehicle is already alongside you;
    • the system reacts to fixed objects, such as a crash barrier or a wall in a bend;
    • the system is temporarily unavailable or shows a fault warning;
    • the warning behaves differently in rain, with dirt, or after rear bumper damage.

    Why might the Blind Spot Warning react differently than expected?

    Blind spot systems usually use radar sensors in the rear bumper. What the system detects can be affected by several factors. A single event isn't enough to establish which factor was the cause; that requires an examination of the vehicle and the situation.

    • dirt, snow or damage around the sensors;
    • damage repair or paintwork on the rear bumper, which can alter sensor alignment;
    • the relative speed of the other vehicle; a vehicle approaching much faster may be detected later;
    • the shape of the road, such as bends or gradients;
    • fixed objects beside the road being interpreted as a vehicle;
    • a technical fault or an issue with sensor calibration.

    What can you do about a Blind Spot Warning problem?

    The Blind Spot Warning supports the driver, but doesn't replace checking over your shoulder. The driver remains responsible for the driving task. Once the situation has passed and you can do so safely, note down the following details:

    • location, date and time;
    • what the system did, or failed to do;
    • the traffic situation, for example an overtaking vehicle or a bend;
    • weather and visibility conditions;
    • whether the rear bumper has recently been repaired or resprayed;
    • any fault warning on the dashboard;
    • whether the same behaviour has happened before.

    Reporting and getting it checked

    Check your car's handbook to see how the system is meant to work and where the sensors are located. Keep the bumper clean according to the manufacturer's instructions.

    If the rear bumper has been repaired or resprayed, or the behaviour occurs regularly, have a qualified garage or service centre check whether the sensors need inspection or calibration.

    Report a Blind Spot Warning problem → A report to ADAS Meldpunt does not replace a technical diagnosis.

    Frequently asked questions

    The system can react to fixed objects beside the road, the shape of the road, or conditions that affect the sensors. Dirt or previous bumper repairs can also play a part. A single alert isn't enough to establish the cause.

    Blind spot systems work within certain conditions, such as a minimum speed difference with the other vehicle. A vehicle approaching much faster may be detected later. Dirt, damage or a fault can also affect how it works.

    Yes, it can. The radar sensors are usually mounted behind the rear bumper. Paintwork or repairs there can affect how the system works. After damage repair, have the sensors checked to make sure they're correctly aligned.

    No. The system is an aid. The driver remains responsible for the driving task and must always check themselves that the space alongside is clear.

    Yes. You can report without giving your name or email address. A registration number is required, though, to link the report to the correct vehicle type. Your registration number is not stored in readable form; it is pseudonymised.

    An independent reporting platform

    ADAS Meldpunt is an independent initiative. It is not affiliated with any vehicle manufacturer, importer, insurer, regulator or other government body.

    We do not sell cars or carry out repairs, and we receive no payment from manufacturers, importers or insurers for the content of reports.

    Reports are used to understand how driver assistance systems work and how they can be used safely, and to identify possible patterns of unexpected or unwanted behaviour. Personal data is kept protected.

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