Collision Warning System* - Limitations. Collision Warning* - Limits of the Camera Sensor

The Collision Warning System in the Volvo S80 (2nd generation, 2013–2016) has limitations that the driver should know in order to increase safety. This section describes typical limits of the system and the camera sensor. It also explains how the driver can make optimal use of the system and avoid malfunctions. This keeps its benefit high in everyday driving.

Collision warning* - Limitations

The function has certain limitations. For example, it is only active above a speed of approx. 4 km/h.

The visual warning of the forward collision warning (see (1) in the illustration) can be difficult to see in strong sunlight, under reflections, when wearing sunglasses, or if the driver is not looking straight ahead. The warning tone should therefore always be switched on.

On slippery roads, the braking distance is longer, which can reduce the ability to avoid a collision. In such situations, the ABS and ESC systems provide the best possible braking force while maintaining stability.

CAUTION

The visual warning can be temporarily deactivated when the interior temperature is high, for example due to strong sunlight.

If this occurs, the warning tone is activated even if it is switched off in the menu system.

• Warnings may not occur if the distance to the vehicle ahead is short or if steering wheel and pedal movements are large,
  for example when driving actively.

WARNING

Warnings and braking maneuvers may be triggered late or may not occur if the traffic situation or external conditions prevent the radar or camera sensor from correctly detecting a pedestrian, a vehicle ahead, or a bicycle.

The sensor system can detect pedestrians and cyclists only to a limited extent²⁷. The system can therefore trigger effective warnings or braking maneuvers at speeds up to 50 km/h. For stationary or slow-moving vehicles, warnings and braking maneuvers are effective at speeds up to 70 km/h.

Warnings for stationary or slow-moving vehicles may not occur due to darkness or poor visibility.

Warning and braking maneuvers for pedestrians and cyclists are switched off at speeds above 80 km/h.

The forward collision warning uses the same radar sensor as adaptive cruise control. Read further about the limitations of the radar sensor.

If the warnings occur too often and are perceived as disturbing, the warning distance can be reduced. The system then triggers the warnings at a later point, and the total number of warnings is reduced.

When reverse gear is engaged, the forward collision warning with automatic braking is temporarily deactivated.

Because the forward collision warning with automatic braking is not activated at low speeds, below 4 km/h, the system does not intervene in situations where your vehicle approaches a vehicle ahead very slowly, for example when parking.

In situations where the driver is driving actively and attentively, the collision warning may be delayed slightly in order to minimize unnecessary warnings.

If automatic braking has prevented a collision with a stationary object, the vehicle remains stopped for a maximum of 1.5 seconds. If the vehicle was braked because of a vehicle ahead, the speed is reduced to the speed of the vehicle ahead.

In vehicles with a manual transmission, the engine stops if automatic braking has brought the vehicle to a stop and the driver does not press the clutch pedal in time.

Related information

- Collision warning system

²⁷ For cyclists, the warning and full braking may occur very late or at the same time.

Collision warning* - Limitations of the camera sensor

The "Forward collision warning with automatic braking and pedestrian and cyclist detection" supports the driver if there is a risk of colliding with a pedestrian, or with a vehicle or bicycle that is stopped or traveling in the same direction in front of the vehicle.

This function uses the vehicle's camera sensor, which has certain limitations.

In addition to the forward collision warning with automatic braking, the vehicle's camera sensor is also used for the following functions:

• Automatic high beam
• Traffic sign recognition
• Driver Alert Control - DAC
• Lane assist

CAUTION

Keep the area of the windshield in front of the camera sensor free of ice, snow, condensation and dirt.

Nothing may be stuck or mounted on the windshield in front of the camera sensor, as this could impair or prevent the function of one or more systems that depend on the camera.

The camera sensor has limitations similar to the human eye, i.e. it "sees" less well, for example in darkness, heavy snowfall, rain, or dense fog. Under these conditions, camera-based functions may be severely restricted or temporarily deactivated.

Strong backlight, reflections on the road surface, a snow- or ice-covered road, a dirty road, or unclear lane markings can also severely affect the function that uses the camera sensor to detect the road as well as pedestrians and other vehicles.

The field of view of the camera sensor is limited, so pedestrians, bicycles, and vehicles may not be detected, or may be detected later than expected, in certain situations.

At very high temperatures, the camera is temporarily switched off for approx. 15 minutes after the engine is started to protect the camera function.

Troubleshooting and action

If the message Windshield sensors obstructed. See manual appears in the display, the camera sensor is blocked and cannot detect pedestrians, cyclists, vehicles, or road markings in front of the vehicle.

This also means that, in addition to the forward collision warning with automatic braking, the following functions are not fully available:

• Automatic high beam
• Driver Alert Control
• Traffic sign recognition

The following table shows possible causes for the display of the message and suitable measures.

Cause	Action
The windshield surface in front of the camera is dirty or covered with ice or snow.	Remove dirt, ice, and snow from the windshield surface in front of the camera.
In dense fog, heavy rain, or snow, the camera does not "see" sufficiently well.	No action required.

The camera sometimes does not work in heavy precipitation. The windshield surface in front of the camera is clean, but the message is still displayed. Wait briefly. It may take a few minutes for the camera to measure visibility. Dirt has collected between the inside of the windshield and the camera. To clean the windshield behind the camera housing, contact a workshop. A Volvo authorized dealer is recommended.

Related information

- Collision warning system

The collision warning system in the Volvo S80 (2nd gen) has certain limitations that the driver should be aware of. The system does not work reliably in all light, weather and traffic conditions, and it never relieves the driver of responsibility.

The camera sensor has limitations similar to those of the human eye. In darkness, heavy rain or backlight, object detection may be impaired. Regular cleaning of the sensors is essential for full functionality.

FAQ

When might warnings not be triggered?
During active driving, poor visibility or strong sunlight, the system may warn late or not at all.

Why is braking for pedestrians and cyclists deactivated above 80 km/h?
Because at these speeds the system cannot react reliably.