A coolant circuit (10) includes at least one heat source (12), a radiator
(14), and a bypass line (22), which connects a radiator inlet (18) to a
radiator return (20) and whose junction (24) has a control valve (26)
disposed on it, whose throttle body (58) can be electrically triggered as
a function of operating parameters and environmental parameters by means
of at least one control unit (40, 42) and divides the coolant flow between
the radiator inlet (18) and the bypass line (22). According to a
characteristic curve of the control valve (26), the control unit (40, 42)
determines a set-point value (50) for the position of the throttle body
(58), which sets a ratio of the radiator volume flow to the total coolant
flow at the control valve (26).
