Anti-lock Brake System (ABS)

The ABS system in your vehicle performs a self-diagnostic test when the vehicle first reaches the speed of approximately 12 mph (20 km/h). The brake pedal will pulsate several times and a sound may be audible from the ABS control module. This is normal.
See also:
Heated rear seats
Heat control for the outboard seating positions
is done in the same way as for the front seats. ...
Comfort and convenience
While the interior of the Volvo S40 places an emphasis on style, form has not
been allowed to take precedence over function. The fascia ergonomics have been
carefully designed and drivers will fin ...
Function
A vehicle towing a trailer may begin to sway for
various reasons. Normally this only occurs at
high speeds but, for example, if the trailer is
overloaded or if the load is unevenly distributed
...
