A belt pretensioner and force limiter in a vehicle having a piston-cylinder device with a cylinder chamber containing an explosive charge in which the piston has a piston rod that protrudes from the cylinder and is joined to a cable. The belt tensioning mechanism includes an idler arm pivotally mounted with respect to the mower deck such that the idler arm pivots about an idler arm pivot. After each of these exposures, the pixel signals of individual pixels are intermittently read out at predetermined pixel intervals. An expansion element, which radially expands the expansion plug part, can be inserted into the passage opening. The driving circuit is coupled between the fans and temperature sensing circuit, and comprises a fully powered operating mode and a power-saving operating mode, wherein the driving circuit selects different operating modes in accordance with the sensing signal, and generates a fan driving signal controlling the speed of the fans.