AEB stands for Autonomous Emergency Braking. It's the safety system that brakes the car automatically when a collision looks unavoidable and the driver hasn't reacted in time. Now required by UK vehicle safety law on new car types, and standard fitment on most cars from 2018 onwards.
AEB = Autonomous Emergency Braking. The system watches the road ahead, detects when a collision with a car, pedestrian, cyclist or animal is about to happen, warns the driver, and brakes the car itself when the driver doesn't react in time.
It's one of the most consequential features in modern car safety. Independent road-safety studies have consistently found AEB-equipped cars are involved in far fewer rear-end collisions than the rest of the fleet. UK vehicle safety law now requires AEB on new car types, with the rollout to all newly-registered cars staged over the next few years.
Despite the name, AEB doesn't make decisions like a self-driving car. It's a single-purpose collision-avoidance feature operating in the background. The driver is still in control at all times. AEB only activates when it detects a high probability of an imminent crash that the driver isn't responding to.
AEB uses one or both of two sensor types, depending on the make and model.
Forward-facing camera. Usually mounted behind the windscreen near the rear-view mirror. The camera reads the road, identifies vehicles, pedestrians and cyclists, and calculates closing speed. Some makes use the camera alone for AEB (Honda Sensing, Toyota Safety Sense base versions). Camera-only AEB tends to work better in good visibility, less well at night or in heavy rain.
Front radar. Usually mounted behind the bumper, often hidden behind the manufacturer's grille badge (this is why a badge swap can knock the system out of alignment). Radar measures distance and closing speed directly, and works in conditions where the camera struggles. Most premium platforms (BMW, Mercedes, Audi) and most modern VAG cars use radar plus camera in a sensor-fusion setup.
Sensor fusion. When both camera and radar are present, the AEB system cross-checks each input against the other before triggering. This is why fusion-based AEB is less prone to false braking than camera-only or radar-only systems.
When the system calculates that a collision is unavoidable and the driver hasn't braked, it does three things in sequence: audible warning, pre-conditioning of the brake system (pads moved against the disc, brake assist primed), and full braking application if the driver still doesn't respond. On some cars the seatbelts pre-tension as part of the same sequence.
The same triggers as any forward-mounted ADAS sensor. AEB depends on both the windscreen camera and the front radar being correctly aimed, so anything that disturbs either will throw the system out of tolerance.
The common triggers in our network:
Yes. AEB (Autonomous Emergency Braking) and Automatic Emergency Braking refer to the same system. Different sources use different expansions of the acronym. Manufacturers also use their own brand names (Front Assist on VW, Pre-Sense on Audi, Honda Sensing, Toyota Safety Sense Pre-Collision) for the same underlying feature.
On new car types approved for the UK market, yes, under UK vehicle safety law. The rollout to all newly-registered cars is staged over the next few years. Cars built before then often have AEB voluntarily (most new models since 2018 carry it), but it isn't strictly required by law on those vehicles.
On most cars yes, through the touchscreen menu, though under current UK rules the system has to default to 'on' every time the car is started. Disabling AEB doesn't void anything legally for now, but it does mean you lose the collision-avoidance benefit and most insurers expect the system to be active when assessing risk.
Phantom braking is almost always a calibration issue. The forward camera or radar is running on out-of-tolerance reference data after a windscreen swap, bumper repair, or sensor disturbance, and is misreading shadows, road markings, or low-clearance bridges as imminent obstacles. Recalibration usually fixes it. Honda Sensing with aftermarket glass and Hyundai Tucson are the two patterns we see most often in our work.
Most AEB systems are calibrated for urban speeds (typically 0 to 50 mph) for collision avoidance, with collision mitigation (reducing impact rather than fully avoiding) extending up to 70 mph or higher on premium platforms with radar-camera fusion. The detailed activation range depends on the specific car and the type of obstacle (vehicle, pedestrian, cyclist). Manufacturer specifications cover the exact thresholds.
If the AEB warning hasn't cleared after a windscreen swap, bumper repair or accident, head to the homepage form. We come back with the calibration tier, the nearest accredited workshop, and the soonest available slot.