A system for transmitting power to vehicle wheels includes a transmission output connected to a first wheel set, a planetary gearset including an input and an output, whose speed is greater than a speed of the gearset input, and a coupler having a variable torque capacity, driveably connecting the transmission output and the gearset input. For example, a cyclic redundancy checksum may be computed in the processor itself responsive to the user-level instruction. The control allows a controlled rollback by making the intervention by the system to be perceived little disturbing, but at the same time in particular in case of strong incline of the road does not render the driver non-informed about the actual incline.