Cooling fan control method for vehicle

A method for controlling a cooling fan for a vehicle to adjust an operation speed of a first cooling fan and a second cooling fan disposed in a cooling module based on a running state and an air conditioner operation of the vehicle, wherein the cooling module includes a stack radiator, an electrical equipment radiator disposed in front of the stack radiator, a condenser disposed in parallel with reference to a width direction of the electrical equipment radiator and the vehicle, and the first and second cooling fans provided at positions respectively corresponding of the electrical equipment radiator and the condenser in rear of the stack radiator, comprising:

• turning on, by a controller, a starting of the vehicle to be driven;
• sensing, by the controller, a stack temperature and setting a first required speed of the first and second cooling fans required by the stack radiator;
• sensing, by the controller, a temperature of the electrical equipment and setting a second required speed of the first cooling fan required by the electrical equipment;
• determining, by the controller, whether the air conditioner is operated;
• sensing, by the controller, an air conditioner pressure and setting a second required speed of the second cooling fan required by the condenser in response to determining that the air conditioner is operated;
• determining, by the controller, whether the first required speed of the first and second cooling fans is greater than or equal to the second required speed of the first cooling fan and the first required speed of the first and second cooling fan is greater than or equal to the second required speed of the second cooling fan;
• setting, by the controller, the first and second cooling fans as the first required speed when the first required speed of the first and second cooling fans is greater than or equal to the second required speed of the first cooling fan and the first required speed of the first and second cooling fan is greater than or equal to the second required speed of the second cooling fan;
• determining, by the controller, whether an absolute value for a difference of a predetermined required speed of the first cooling fan and a predetermined required speed of the second cooling fan is greater than or equal to a resonance frequency revolutions per minute (RPM) (α);
• operating, by the controller, the first and second cooling fans with the predetermined required speed when the absolute value for the difference of the predetermined required speed of the first cooling fan and the predetermined required speed of the second cooling fan is greater than or equal to the resonance frequency RPM (α);
• determining, by the controller, whether a coolant temperature and the air conditioner pressure of a stack and the electrical equipment are within a predetermined setting value;
• and
• completing, by the controller, the control of the cooling fans in response to determining that the coolant temperature and the air conditioner pressure of the stack and the electrical equipment are within a predetermined setting value.