XC90 Twin Engine

2016

Driver support

Limitations of the radar unit

Updated 7/23/2018

The radar unit has certain limitations - which in turn also limits those functions that use the unit.

Blocked unit

The marked area must be kept free from stickers, objects etc.

The marked area must be kept free from stickers, objects etc.

The radar unit is placed inside the upper section of the windscreen together with the car's camera unit.

Important

Do not place, stick or mount anything on the outside or inside of the windscreen in front of or around the camera and radar unit — this can interfere with camera and radar-dependent functions.

If the driver display shows this symbol with the message Windscreen sensorSensor blocked, see Owner's manual, it means that the camera and radar unit cannot detect other vehicles in front of the car.

The following table presents examples of possible causes for a message being shown, along with the appropriate action:

Cause

Action

The windscreen surface in front of the camera and radar unit is dirty or covered with ice or snow.

Clean dirt, ice and snow from the windscreen surface in front of the camera and radar unit.

Thick fog and heavy rain or snow block the radar signals or the camera view.

No action. Sometimes the unit does not work during heavy rain or snowfall.

Water or snow from the road surface swirls up and blocks the radar signals or camera view.

No action. Sometimes the unit does not work on a very wet or snow-covered road surface.

Dirt has appeared between the inside of the windscreen and the camera and radar unit.

Visit a workshop to have the windscreen inside the unit's cover cleaned - an authorised Volvo workshop is recommended.

Note

Keep the windscreen clean in front of the camera and radar unit.

The capacity of the radar unit to detect vehicles ahead is reduced significantly if:

  • the speed of vehicles in front is significantly different from your own speed

Limited field of vision

The radar unit has a limited field of vision. In some situations another vehicle is not detected, or the detection is made later than expected.

The radar unit

The radar unit's field of vision.

Sometimes the radar unit is late at detecting vehicles at close distances - e.g. a vehicle that drives in between the car and vehicles in front.
Small vehicles, such as motorcycles, or vehicles not driving in the centre of the lane can remain undetected.
In bends, the radar unit may detect the wrong vehicle or lose a detected vehicle from view.

Low trailers

Low trailer in radar shadow.

Low trailer in radar shadow.

Low trailers can also be difficult for the radar unit to detect, or are not detected at all - the driver should therefore be particularly careful when driving behind low trailers when the adaptive cruise control or Pilot Assist is activated.

High temperature

At very high temperatures the camera and radar unit can temporarily be switched off for about 15 minutes after the engine is started so as to protect the unit's electronics. The camera and radar unit restarts automatically when the temperature has fallen sufficiently.

Damaged windscreen

Important

If a crack, scratch or stone chip in the windscreen in front of one of the camera and radar unit “windows” covers an area of approx. 0.5 x 3.0 mm or larger, a workshop must be contacted to have the windscreen replaced. An authorised Volvo workshop is recommended.

If not rectified it can lead to reduced performance for the driver support systems that use the camera and radar unit.

To avoid the risk of failed, deficient or reduced operation of ™driver support systems that use the radar unit, the following also applies:

  • Volvo recommends against repairing cracks, scratches or stone chips in the area in front of the camera and radar unit. Instead, the whole windscreen should be replaced.
  • Before replacing a windscreen, contact an authorised Volvo workshop to verify that the correct windscreen is ordered and fitted.
  • The same type or Volvo-approved windscreen wipers must be fitted during replacement.

Important

When the windscreen is replaced, the camera and radar unit must be recalibrated at the workshop to ensure the functionality of all the car’s camera and radar-based systems. An authorised Volvo workshop is recommended.

Maintenance

In order that the radar and camera unit shall function correctly, the windscreen in front of the unit must be kept clear of dirt, ice and snow, and be cleaned regularly with water and car shampoo.

Note

Dirt, ice and snow covering the camera and radar unit will reduce its function and may prevent measurement.


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