Citroen C4: Active Safety Brake with Collision Risk Alert and Intelligent emergency braking assistance

For more information, refer to the General recommendations on the use of driving and manoeuvring aids.

This system:

- warns the driver that their vehicle is at risk of collision with the preceding vehicle, a pedestrian or a cyclist.

- reduces the vehicle's speed to avoid a collision or to limit its severity.

The system also takes motorcyclists into account.

It may also react on animals. Animals (especially animals smaller than 0.5 m) and objects on the road are not necessarily detected.

This system includes three functions:

- Collision Risk Alert.

- Intelligent emergency braking assistance (iEBA).

- Active Safety Brake (automatic emergency braking).

The vehicle has a multifunction camera located at the top of the windscreen and, depending on version, a radar located in the front bumper.

This system does not replace the need for driver vigilance.

This system is designed to assist the driver and improve road safety.

It is the driver's responsibility to continuously monitor traffic conditions in accordance with applicable driving regulations.

As soon as the system detects a potential collision, it prepares the braking circuit. This may cause a slight noise and a slight sensation of deceleration.

• Operating conditions and limits
• Collision Risk Alert
• Active Safety Brake
• Deactivation/Activation

Operating conditions and limits

Vehicle moving forward without trailer.

Brake system operational.

Seat belts fastened for all passengers.

Stabilised speed on roads with no or low curvature.

This warning lamp lights up on the instrument panel without any additional message, to indicate that the automatic braking system is not available.

This is a normal behavior indicating that a condition is not fulfilled and which does not request the support of a workshop.

In any situations with ignition on where automatic braking presents a risk, deactivating the system is recommended, for instance:

- Towing a trailer (particularly a trailer without its own braking system).

- Carrying long objects on roof bars.

- Driving with snow chains.

- Using an automatic car wash.

- Performing any maintenance (e.g. changing a wheel, working inside the engine compartment).

- Placing the vehicle on a rolling bench in a workshop.

- Towing the vehicle.

- Following a damage of the windscreen close to the detection camera.

The system is automatically deactivated when the use of certain types of "space-saver" spare wheel (smaller diameter) is detected, or if a fault with the brake pedal switch or with the right or left brake lamp is detected.

Following a severe crash (e.g. with airbag deployment), the system is automatically deactivated.

Have it checked by a CITROËN dealer or a qualified workshop.

The system performance may be degraded or not available by:

- Sensor covered with snow, ice, slush, mud or dirt.

- Windscreen damaged or smeared, with blurred view or covered with foreign items (e.g. stickers).

- Damaged front bumper (or deformed in the past) or covered with foreign items (e.g. stickers).

- Front camera out of regular position or missing cover.

- Brake discs cooling process is on-going.

- In curves.

- System initialization process after battery disconnection.

- Sun or lights shining into the front camera lens.

- Adverse environmental conditions (e.g. rain, fog or snow).

- Vehicle ahead creating road spray.

The system performance may be affected by:

- Vehicle stability system in progress.

- Vehicle battery voltage out of range.

- Wet road reflecting lights.

- Close vehicles ahead.

- Tractors, muddy vehicles or vehicles with a trailer.

- Banked roads.

- Winding or hilly roads.

- Poor lighting conditions.

- Sudden lighting changes.

- Vehicle modifications (e.g. tyres).

In case the detection is degraded or temporarily unavailable by environment conditions, then a driver indication is not displayed (because a driver action is not requested).

It can be dangerous to drive if the brake lamps are not in perfect working order.

The driver must not overload the vehicle (keep within the GVW limit and load height limits for roof bars).

Collision Risk Alert

This function warns the driver if there is a risk of collision with the preceding vehicle, or with a pedestrian or cyclist.

Modifying the alert trigger threshold

The trigger threshold determines the sensitivity with which the function warns of the risk of collision.

The selected threshold is memorised when the ignition is switched off.

 With Touch screen BLUETOOTH audio system or MyCitroën Play

The threshold is set via the Driving touch screen menu.

► Select one of the three pre-defined thresholds: "Far", "Normal" or "Close".

 With MyCitroën Drive Plus

The threshold is set via the ADAS touch screen application.

► Select one of the 3 preset thresholds: "Far", "Medium" or "Near".

Operation

Depending on the collision risk detected by the system and the alert trigger threshold chosen by the driver, different levels of alert may be triggered and displayed on the instrument panel.

The system takes into account the vehicle dynamics, the difference speed of the own vehicle and the object identified for the 6 collision risk, and the operation of the vehicle (e.g. actions on the pedals, steering wheel) to trigger the alert at the most relevant moment.

(orange)

Level 1: visual alert only, warning that the preceding vehicle is very close.

The message "Vehicle close" is displayed.

(red)

Level 2: visual and audible alert, warning that a collision is imminent.

The message "Brake!" is displayed.

Level 3: a micro-braking may be given, confirming the risk of collision (optional).

While approaching a vehicle too quickly, the level 2 alert may be displayed directly.

Important: the level 1 alert depends on the trigger threshold selected. It reacts only on moving vehicles. It is disabled automatically at lower speed.

It is possible that collision warnings are not given, are given too late or seem unjustified.

The driver must always stay in control of the vehicle and be prepared to react at any time to avoid an accident.

If you select "Far" in the touch screen, then the system warns sooner. This increases the safety but increases also the amount of alerts, if the legal safety distance is not kept.

To reduce the alert occurrence, you can change the setting to either of the other two.

Intelligent emergency braking assistance (iEBA)

This function increases vehicle deceleration if the driver does not brake enough to avoid a collision.

This assistance is only provided if the driver presses the brake pedal.

Active Safety Brake

This function, also called "automatic emergency braking", intervenes after the acoustic alert if the driver does not operate the brake pedal quickly enough.

The system aims at reducing the speed of impact or avoiding a collision if the driver fails to react.

The speed will be reduced by a maximum of 12 mph (20 km/h) (versions with camera only) or by a maximum of 30 mph (50 km/h) (versions with camera and radar).

Operation

The system operates in the following speed ranges:

- Between 3 mph and 50 mph (5 km/h and 80 km/h) when a stationary vehicle is detected.

- Between 3 mph and 50 mph (5 km/h and 80 km/h) when a pedestrian is detected.

- Between 3 mph and 50 mph (5 km/h and 80 km/h) when a cyclist is detected (versions with camera and radar only).

- Between 3 mph and 50 mph (5 km/h and 80 km/h) (versions with camera only) or 87 mph (140 km/h) (versions with cameras and radar) when a moving vehicle is detected.

This warning lamp flashes (for approximately 10 seconds) as soon as the function applies the vehicle's brakes.

During the flashing time, the function is not available.

With an automatic gearbox or drive selector, in the event of automatic emergency braking, keep the brake pedal depressed, also after a complete stop is reached, to prevent the vehicle from rolling away.

With a manual gearbox, in the event of automatic emergency braking bringing the vehicle to a complete stop, the engine may stall.

The driver can override the automatic emergency braking at any time by strongly turning the steering wheel (evasive manoeuver) and/or by firmly pressing the accelerator pedal.

The brake pedal may feel hard and vibrate slightly while the function is operating.

If the vehicle comes to a complete stop, automatic braking is maintained for 1 to 2 seconds.

Deactivation/Activation

By default, the system is automatically activated at every engine start.

With Touch screen BLUETOOTH audio system or MyCitroën Play

The settings are changed via the Driving touch screen menu.

With MyCitroën Drive Plus

The settings are changed via the ADAS touch screen application.

Deactivation of the system is signalled by the illumination of this warning lamp, accompanied by the display of a message.

The system cannot be deactivated above 10 km/h.

Malfunction

This warning lamp lights up on the instrument panel with the message "Audible Warning System fault: Repair needed" if the audible warning system is in failure.

The system may be disturbed or unavailable.

Have it checked by a CITROËN dealer or a qualified workshop.

This warning lamp lights up on the instrument panel with the message "Driving Assistance Sensor blind: Clean sensor, see User Manual" if the sensor is masked.

This is a normal behavior, which does not request the support of a qualified workshop.

In this case, stop the vehicle and verify if the front camera or the front radar is covered by dirt, mud, sand, snow, ice or anything preventing the sensing.

The system is operational again after the detection field has been cleaned.

In the event of a malfunction, this warning lamp lights up on the instrument panel, accompanied by the display of a message and an audible signal.

Have it checked by a CITROËN dealer or a qualified workshop.

If these warning lamps come on after the engine has been switched off and then restarted, contact a CITROËN dealer or a qualified workshop to have the system checked.

These warning lamps light up on the instrument panel and/or in the warning lamp display for seat belts and front passenger airbag to indicate that the driver's and/or front passenger's seat belt is not fastened (depending on version). The automatic braking system is deactivated until the seat belts are fastened.