Volvo S90 Owner's Manual page 357

In an angled parking slot CTA may be completely "blind"
on one side.
Blind CTA sector.
Sector in which CTA can detect/"see".
However, as your car slowly reverses, the angle it
makes with the obstructing vehicle/object
changes and the blind sector rapidly decreases.
Examples of further limitations
Dirt, ice and snow covering the sensors may
•
reduce the functions and deactivate alerts.
CTA is automatically deactivated if a trailer,
•
bicycle rack or similar is connected to the
car's electrical system.
For optimal performance of CTA, no bicycle
•
rack, luggage carrier or similar should be
mounted on the car's towbar.
NOTE
This function uses the car's camera and radar
units, which have certain general limitations.
Related information
• Cross Traffic Alert* (p. 353)
Limitations for camera and radar unit
•
(p. 329)
DRIVER SUPPORT
355
* Option/accessory.