Power brakes function only when the engine is running

The power brakes utilize vacuum pressure which is only created when the engine is running. Never let the vehicle roll to a stop with the engine switched off.
If the power brakes are not working, considerably higher pressure will be required on the brake pedal to compensate for the lack of power assistance. This can happen for example when towing your vehicle or if the engine is switched off when the vehicle is rolling. The brake pedal feels harder than usual.
See also:
Operation
Press to operate the air quality sensor (normal
setting).
or:
Select one of the following three functions by
pressing 1, 2 or 3 times.
1. The AUT LED lights. The air quality sensor
is now acti ...
Passenger compartment filter
Replace the cabin air filter with a new one at
the recommended intervals. Please refer to
your Warranty and Service Records Information
booklet, or consult a trained and qualified
Volvo servic ...
How BLIS functions in daylight and darkness
Daylight
BLIS reacts to the shape of surrounding vehicles.
The system is designed to help detect
motor vehicles such as cars, trucks, buses,
motorcycles, etc.
Darkness
BLIS reacts to the headl ...
