In a procedure to operate an internal combustion engine with an
electrohydraulic valve control which comprises electrically activated oil
control valves for hydraulic actuators for the actuation of charge-cycle
valves, a motor control unit as well as an output stage unit, which is
connected to the motor control unit via a data link, at least a limited
operation of the internal combustion engine is made possible during a
breakdown of the data bus between the motor control unit and the output
stage unit, in that the output stage unit is transferred into an
autonomous mode of operation during a breakdown of the data link to the
motor control unit.