Volvo FM Handbook page 201

190 Driving
3 Keep the memory button depressed for at least five
seconds.
4 The new ride height is now set. Select ride height.
Restoring the factory-set ride height
It is always possible to restore the ride height the truck
had from the factory.
Road speed must be lower than 30 km/h when the
control box is used.
J7009832
J7009834