Content guide

AEB Introduction

System Activation/Deactivation

Warning and active levels of AEB operation

Additional information

System limitations

System Activation/Deactivation

When you start the engine, AEB is automatically activated. AEB is deactivated in the following situations:

• if there is a malfunction
• if ABS is deactivated or there is a malfunction in the brake system of the vehicle

AEB may also be de-activated by the driver but at next key-on the system resets and AEB will be active again. The system reactivates on ignition cycle, The system is inactive if the EBS/ABS/AEBS system has faults.

If the AEB system develops a fault or there is a fault in the ABS or stability systems, it will no longer function correct and a warning will be displayed.

When the system has been turned off, symbols of AEB with a cross through it, or an exclamation mark, will be displayed in the instrument panel.

There may be an off AEB function optionally which is allowed under ADR97/00 via UN R131, however not all OEMs have the feature available either optionally or designed.

If the feature is available, the AEB system will reset to “on” every time the key is turned on.

Typcically AEB systems are equipped with a counter which is able to record every occurrence of emergency braking of the vehicle. The AEB system will no longer be available at the next start-up if the counter has recorded three automatic emergency braking situations, and the and symbols will be displayed.

This will not result in the vehicle stopping and it can still be driven without the functions offered by the AEB system; nevertheless, the driver must contact their Service Network as soon as possible to reset the counter and restore the functions of the AEB system.

• Remove the vehicle from the danger area as soon as possible while paying attention to the traffic situation.
• Stop the engine and apply the parking brake to prevent the vehicle from rolling away.
• Make sure that the vehicle is in proper working order and that the load is secured properly.

This varies depending on the brand. Collision warning may become active from between 5km/h to 16km/h. Collision mitigation may become active from between 24km/h or fast. However, in some manufacturer’s owners hand books, they also provide an upper speed limit, such as: -

NOTE in the event of inappropriate speed, above 90 km/h, the operation of the system is limited and above 125 km/h the system will be disable automatically. The driver can always by-pass the system by pressing the accelerator pedal to kickdown, activating the turn indicators or by turning the steering wheel.

European HV speed limit is typically 90 km/h, and the ADR97 testing is undertaken at 80km/h. The net result is that its performance due to speed/limited response time, may not perform as expected. The system will continue to operate as expected until it is disabled at truly excess speed above the Australian road speed limts .

ADR97 requires that the emergency braking phase shall not start before a TTC equal to or less than 3.0 seconds. Plus the system must provide warning at 1.4 seconds before the start of emergency braking phase.

Simply at the higher speeds, the systems don’t have time to guarantee full mitigation of the crash.

Radars have a range of 150 metres.

AEB may be impaired or may not function in the following situations: -

• if visibility is poor, e.g. due to snow, rain, fog or heavy spray
• if the carriageway is very narrow and winding
• if the radar sensor is impaired due to interference from other radar sources, such as strong radar reflections in car washes
• poor fitment bullbars, signs, nudge bars, driving lights and light bars installation

AEB may also be impaired or may not function in the following situations with camera enhanced systems:

• if there is glare, e.g. from oncoming traffic, direct sunlight or reflections (e.g. if the carriageway is wet)
• if the windscreen in the area of the camera is dirty, obscured or damaged, e.g. due to a faulty windscreen wiper or a sticker

In some circumstances, AEB does not react correctly in the following situations:

• if vehicles move quickly into the sensor detection range
• on bends with tight radii
• to stationary people
• to pedestrians that are obscured by other objects
• if the typical contour of a pedestrian does not stand out from the background
• if a pedestrian is no longer detected as such, e.g. due to special clothing or other objects
• to people or vehicles moving quickly within the detection range of the sensors
• to people in a tunnel

AEB may recognise pedestrians or cyclists but this is not required by the ADR.

Some systems only react to pedestrians up to a speed of 50 km/h.

AEB should not react:

• to people or animals
• to oncoming vehicles

As a result, AEB might not warn you or intervene in these situations.

3 strikes and you are out!

AEB should only active fully on very rare occurrences. Some system provides limit to emergency brake AEB interventions to 3, after the system needs to be reset by the authorised service provider

Stability control, however does not have this functionality, and too often the feature operates extensively until the vehicle rolls. The driver is not learning that they are driving at or near the physical limit of vehicle stability, repeatedly! Please use the systems event record and diagnostics for driver training.