according to § 29 StVZO

In the case of large, heavy vehicles, the safety tests (SP) are used by experts to check the safety-relevant components and, in particular, the components that are susceptible to wear and repair, even between two HU appointments.

This inspection is mandatory for motor vehicles with a maximum design speed of more than 40 km/h, for trucks, tractor units and semi-trailer tractors with a gross vehicle weight of more than 7.5 tons. Trailers with a gross vehicle weight of more than 10 tons and buses, as well as other vehicles with more than 8 passenger seats, are also subject to SP.

During the safety test, a non-destructive functional and efficiency test is carried out. The test relates to the following 5 safety-relevant assemblies: