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:

    Shortcuts
    Shortcut commands for using the phone can be found in the MY CAR menu system, under Settings Voice settings Voice command list Phone commands and General commands. See page 133 for more informatio ...

    Shiftlock override
    If the vehicle cannot be driven, for example because of a dead battery, the gear selector must be moved from the P position before the vehicle can be moved. 1 Lift away the rubber mat on the ...

    Removing the cover
    1. Press one of the end pieces of the cover inward. 2. Pull the cover carefully upward and outward. The other end will release automatically from its retaining bracket. ...