Power brakes function only when theengine is running

Power brakes function only when theengine is running  - Brake system - Starting and driving - Volvo XC90 Owners Manual - Volvo XC90

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:

    Cargo net
    Cargo net mounted in rear position Your vehicle can be equipped with a cargo net made of strong nylon fabric that helps prevent objects in the cargo area from moving forward into the passenge ...

    Engines
    The Volvo XC90 is available with a choice of two high-performance engines - one diesel and one petrol - both of which produce plenty of power and torque from low engine speeds and through the mid- ...

    All Wheel Drive
    All Wheel Drive (AWD) – general information Your Volvo can be equipped with an electronically controlled All Wheel Drive system, which means that power is distributed automatically between the fr ...