However, the sensor has limitations and has poorer functionality - or none at all - in e.g. heavy snowfall or rain, dense fog, dust storms or white-out situations. Mist, dirt, ice or snow on the windscreen may disrupt the function.
Low-hanging objects, e.g. a flag/pennant for projecting load, or accessories such as auxiliary lamps and bull bars that are higher than the bonnet limit the function.
The laser beam from the sensor in City Safety™ measures how the light is reflected. The sensor cannot detect objects with low reflection capacity. The rear sections of the vehicle generally reflect the light sufficiently thanks to the number plate and rear light reflectors.
On slippery road surfaces the braking distance is extended, which may reduce the capacity of City Safety™ to avoid a collision. In such situations the ABS and DSTC systems will provide best possible braking force with maintained stability.
When your own car is reversing, City Safety™ is temporarily deactivated.
City Safety™ is not activated at low speeds - under 4 km/h, which is why the system does not intervene in situations where a vehicle in front is being approached very slowly, e.g. when parking.
Driver commands are always prioritised, which is why City Safety™ does not intervene in situations where the driver is steering or accelerating in a clear manner, even if a collision is unavoidable.
When City Safety™ has prevented a collision with a stationary object the car remains stationary for a maximum of 1.5 seconds. If the car is braked for a vehicle in front that is moving, then speed is reduced to the same speed as that maintained by the vehicle in front.
On a car with manual gearbox the engine stops when City Safety™ has stopped the car, unless the driver manages to depress the clutch pedal beforehand.
Note
- Keep the windscreen surface in front of the laser sensor free from ice, snow and dirt (see the illustration for sensor location).
- Do not affix or mount anything on the windscreen in front of the laser sensor
- Remove ice and snow from the bonnet - snow and ice must not exceed a height of 5 cm.
Fault tracing and action
If the message Windscreen Sensors blocked is shown in the combined instrument panel it indicates that the laser sensor is blocked and cannot detect vehicles in front of the car. This means in turn that City Safety™ is not operational.
The Windscreen Sensors blocked message is not shown for all situations in which the laser sensor is blocked. The driver must therefore be diligent about keeping the windscreen and area in front of the laser sensor clean.
The following table presents possible causes for the message being shown, along with suggestions for appropriate action.
| Cause | Action |
|---|---|
| The windscreen surface in front of the laser sensor is dirty or covered with ice or snow. | Clean the windscreen surface in front of the sensor from dirt, ice and snow. |
| The laser sensor field of vision is blocked. | Remove the blocking object. |
Important
If there are cracks, scratches or stone chips in the windscreen in front of either of the laser sensor's "windows" and they cover a surface of approx. 0.5 x 3.0 mm (or larger), then a workshop must be contacted for replacement of the windscreen (see the illustration for sensor location) - an authorised Volvo workshop is recommended.
Failure to take action may result in reduced performance for City Safety™.
To avoid the risk of failed, deficient or reduced operation for City Safety™, the following also applies:
- Volvo recommends that you do not repair cracks, scratches or stone chips in the area in front of the laser sensor - 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.