A steering control unit and to a method of controlling the steering of a multi-unit vehicle is provided, the vehicle having a plurality of vehicle parts movably connected to one another and a plurality of steerable axle units. A first axle control unit is in conjunction with a first steerable axle unit and at least one second axle control unit is in conjunction with at least one second steerable axle unit. The steering control system has a central control module that is connected to the axle control units via a common data line for exchange of steering angle data. The axle control units have data interfaces for communication via the data line. The data interfaces transfer mutually identical data formats, whereby the steering control system is set up in a modular manner with a variable number of axle control units that can be integrated.