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:

    Summary
    • The camera is activated when the gear selector is moved to R (this can be changed in the MY CAR menu) and the image is shown on the center console display. • When backing up, two solid lines ...

    Windshield wipers
    1 Thumb wheel 2 Rain sensor on/off Windshield wipers off If the lever is in the 0 position and you move it upwards, the wipers will sweep one stroke at a time for as long as you hold the lev ...

    Interior rearview mirror
    Auto-dim function An integrated sensor reacts to headlights from following traffic and automatically reduces glare in the mirror. ...