Abstract:
An apparatus and a method for controlling a cooling fan of a vehicle are capable of preventing a fan motor from being damaged by locking the fan motor in cold weather conditions. The apparatus includes: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, where the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2015-0167950 filed in the Korean Intellectual Property Office on Nov. 27, 2015, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    (a) Technical Field 
         [0003]    The present invention relates to an apparatus for controlling a cooling fan of a vehicle, and more particularly, to an apparatus and a method for controlling the cooling fan capable of preventing damage to a fan motor by locking the fan motor in cold weather conditions, such as winter. 
         [0004]    (b) Description of the Related Art 
         [0005]    Since a large amount of heat is generated in an engine of a vehicle, a coolant is circulated in the vicinity of the engine in order to cool the engine, thereby lowering the temperature of the engine. A heated coolant is heat-radiated in a radiator, and a cooling fan is installed in an engine compartment of the vehicle in order to improve a heat radiation effect of the radiator. 
         [0006]    The cooling fan maintains a temperature of the coolant in an appropriate condition to prevent overheat of the engine and allow performance of the engine to be optimized. The cooling fan is primarily driven by a motor. 
         [0007]    In cold weather conditions, moisture or snow is introduced into the cooling fan, such that freezing of the cooling fan often occurs. Therefore, at the time of the freezing of the cooling fan, the cooling fan is not operated even in a condition in which the cooling fan is turned on. 
         [0008]    In such conditions, the cooling fan is not generally operated. However, when a driver presses a defrost button in order to remove fog or frost, an air conditioner is operated, such that an air conditioner refrigerant pressure gradually rises. When the air conditioner refrigerant pressure reaches a predetermined pressure, it arrives at a region in which the cooling fan should be operated. However, the cooling fan is not operated due to locking of the motor caused by the freezing of the cooling fan. In addition, when a locking time becomes long, the motor may be damaged or, in extreme circumstances, a fire may occur in the engine compartment. 
         [0009]    When an external temperature sensor is present in the vehicle, it is possible that the cooling fan is not operated at sub-zero temperatures. However, when an external temperature sensor is not mounted in the vehicle, an external temperature may not be checked, such that a control may not be performed to prevent operation of the cooling fan at sub-zero temperatures. In addition, in such a case, the cooling fan is operated in a predetermined condition, such that the cooling fan may be frozen, thereby causing damage to the motor. The damage to the motor generates overheat of the engine, which can result in significant repair costs. 
         [0010]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0011]    The present invention provides an apparatus and a method for controlling a cooling fan of a vehicle capable of locking a fan motor on the basis of an intake air temperature and an air conditioner refrigerant pressure in order to prevent damage to the fan motor in cold weather conditions. 
         [0012]    Further, the present invention provides an apparatus and a method for controlling a cooling fan of a vehicle capable of operating the cooling fan in the case in which a coolant temperature is greater than or equal to a reference temperature. 
         [0013]    An exemplary embodiment of the present invention provides an apparatus for controlling a cooling fan of a vehicle, the cooling fan being installed in an engine compartment of the vehicle, including: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, wherein the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure. 
         [0014]    The confirm a first change rate of the air conditioner refrigerant pressure for a first measurement time, operate the cooling fan through the fan motor by providing the operation signal to the fan motor for a second measurement time, confirm a second change rate of the air conditioner refrigerant pressure for the second measurement time, and stop the operation of the cooling fan depending on the first change rate and the second change rate. 
         [0015]    The controller may calculate a comparison value on the basis of the first change rate and the second change rate, decide whether or not the comparison value is less than or equal to a decision reference, and stop the operation of the cooling fan in the case in which the comparison value is not maintained for a duration in a state in which the comparison value is less than or equal to the decision reference. 
         [0016]    The apparatus for controlling a cooling fan of a vehicle may further include: a state detector including at least one of an intake air temperature measurer measuring the intake air temperature; a coolant measurer measuring a coolant temperature; a speed measurer measuring a vehicle speed; and a pressure measurer measuring the air conditioner refrigerant pressure. 
         [0017]    The controller may provide the operation signal to the fan motor and lock the fan motor depending on the change rate of the air conditioner refrigerant pressure for the measurement time, when a compressor is operated and a vehicle speed is 0. 
         [0018]    The controller may turn off a compressor when the intake air temperature is not present within the predetermined temperature, and operate the cooling fan when a coolant temperature is greater than or equal to a reference temperature in a state in which the controller turns off an air conditioner switch. 
         [0019]    Another exemplary embodiment of the present invention provides a method for controlling a cooling fan of a vehicle by an apparatus for controlling a cooling fan of a vehicle, including: confirming an ignition-off time for which an ignition was turned off when the ignition is turned on; deciding whether or not the ignition-off time exceeds a decision-possible time; deciding whether or not an intake air temperature is present within a predetermined temperature when the ignition-off time exceeds the decision-possible time; and locking a fan motor depending on a change rate of an air conditioner refrigerant pressure for a measurement time when the intake air temperature is present within the predetermined temperature. 
         [0020]    In an exemplary embodiment of the present invention, it is possible to prevent the fan motor from freezing in cold weather conditions, such as winter, and thus prevent damage by stopping operation of the fan motor. 
         [0021]    In addition, in the case in which the coolant temperature is greater than or equal to the reference temperature, the cooling fan is operated, thereby making it possible to prevent overheat of the engine. 
         [0022]    Other effects that may be obtained or are predicted by an exemplary embodiment of the present invention will be explicitly or implicitly described in a detailed description of the present invention. That is, various effects that are predicted according to an exemplary embodiment of the present invention will be described in the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a block diagram showing an apparatus for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention. 
           [0024]      FIG. 2  is a flow chart showing a method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
           [0025]      FIG. 3  is an illustrative view showing a control method when an air conditioner switch is turned off in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
           [0026]      FIG. 4  is a flow chart showing a method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
           [0027]      FIG. 5  is an illustrative view for describing the method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
           [0028]      FIG. 6  is an illustrative view for describing a first change rate and a second change rate in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0029]    It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
         [0030]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof. 
         [0031]    Further, the control logic of the present invention may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN). 
         [0032]    Hereinafter, an operation principle of an apparatus and a method for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention will be described in more detail with reference to the accompanying drawings. 
         [0033]    However, drawings provided below and a detailed description to be provided below relate to one preferred exemplary embodiment of several exemplary embodiments for effectively describing features of the present invention. Therefore, the present invention is not limited to only the following drawings and description. 
         [0034]    Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
         [0035]      FIG. 1  is a block diagram showing an apparatus for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention. 
         [0036]    The apparatus  50  for controlling a cooling fan of a vehicle includes a state detector  100 , a controller  110 , an air conditioner switch  120 , a compressor  125 , a relay  130 , a connector  140 , a blower assembly  150 , and a cooling fan  160 . 
         [0037]    The state detector  100  detects information required in order to control the cooling fan  160 . The state detector  100  includes an intake air temperature measurer  102 , a speed measurer  104 , a pressure measurer  106 , and a coolant temperature measurer  108 . 
         [0038]    The intake air temperature measurer  102  measures an intake air temperature, which is a temperature of air introduced into the vehicle, and provides the measured temperature to the controller. 
         [0039]    The speed measurer  104  measure a vehicle speed, which is a speed of the vehicle, and provides the measured vehicle speed to the controller. 
         [0040]    The pressure measurer  106  measures an air conditioner refrigerant pressure, and provides the measured air conditioner refrigerant pressure to the controller. 
         [0041]    The coolant temperature measurer  108  measures a coolant temperature of an engine, and provides the measured coolant temperature to the controller. 
         [0042]    The controller  110  controls at least one of the state detector  100 , the air conditioner switch  120 , the compressor  125 , the relay  130 , the connector  140 , the blower assembly  150 , and the cooling fan  160 , which are components of the apparatus  50  for controlling a cooling fan of a vehicle, in order to operate or stop the cooling fan  160 . 
         [0043]    The controller  110  confirms an ignition-off time for which an ignition was turned off when the ignition is turned on. The controller  110  confirms a change rate of the air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and the intake air temperature is present within a predetermined temperature. The controller  110  performs a control to lock or normally operate a fan motor  157  depending on the change rate of the air conditioner refrigerant pressure. A method for controlling the cooling fan  160  in the controller  110  will be described in more detail with reference to  FIGS. 2 to 5 . 
         [0044]    For this purpose, the controller  110  may be implemented by at least one processor operated by a predetermined program, which may be programmed to perform the respective steps of a method for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention. 
         [0045]    The air conditioner switch  120  turns on or turns off an air conditioner. That is, the air conditioner switch  120  may turn on or turn off the air conditioner by a driver or the controller  110 . 
         [0046]    The compressor  125  compresses a refrigerant at a high temperature and a high pressure to operate the air conditioner, when the air conditioner is turned on by the air conditioner switch  120 . 
         [0047]    The relay  130  provides an operation signal to the connector  140  depending on a control of the controller  110 . 
         [0048]    The connector  140  receives the operation signal from the relay  130  to drive the fan motor  157 . To this end, the connector  140  includes a high speed connector  143 , a low speed connector  146 , and a ground connector  149 . The high speed connector  143  is directly connected to the fan motor  157 , and the low speed connector  146  is connected to the fan motor  157  through a resistor  153 . The ground connector  149  is connected to the fan motor  157  and a ground. Here, the high speed connector  143 , the low speed connector  146 , and the ground connector  149  may also be formed of a switch. The connector  140  drives the fan motor  157  through the low speed connector  146  and the resistor  153  when it receives a low speed operation signal from the relay  130 . In addition, the connector  140  drives the fan motor  157  through the high speed connector  143  when it receives a high speed operation signal from the relay  130 . 
         [0049]    The blower assembly  150  includes the fan motor  157  and the resistor  153 . 
         [0050]    The fan motor  157  rotates blades included in the cooling fan  160  to operate the cooling fan  160 . 
         [0051]    The resistor  153  adjusts a speed of the fan motor  157 . That is, the larger the resistance value of the resistor  153 , the lower the speed at which the fan motor  157  is driven. 
         [0052]    The cooling fan  160  is driven by the fan motor  157  included in the blower assembly  150 . The cooling fan  160  maintains a temperature of a coolant in an appropriate condition to prevent overheat of the engine and allow performance of the engine to be optimally exhibited. 
         [0053]    Hereinafter, a method for controlling a cooling fan  160  in a vehicle according to an exemplary embodiment of the present invention will be described with reference to  FIGS. 2 to 6 . 
         [0054]      FIG. 2  is a flow chart showing a method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
         [0055]    Referring to  FIG. 2 , the controller  110  confirms whether or not the ignition is turned on (S 210 ). Here, the controller  110  may confirm whether or not the ignition is turned on by receiving an ignition-on signal from an initial detector (not shown). 
         [0056]    The controller  110  confirms the ignition-off time for which the ignition was turned off (S 215 ). That is, the controller  110  may confirm the ignition-off time by counting a time for which the ignition was turned off before the ignition is turned on. 
         [0057]    The controller  110  decides whether or not the ignition-off time exceeds the decision-possible time (S 220 ). Here, the decision-possible time may indicate a reference time for deciding that the vehicle is parked in the night, and may be set by a worker or be set through a predefined algorithm (for example, a program or a probability model). For example, the decision-possible time may be six hours. 
         [0058]    The reason for deciding whether or not the ignition-off time exceeds the decision-possible time as described above is to confirm that the vehicle was parked in the night. In the case in which the vehicle is parked in the night, it may be assumed that an intake air temperature and an external air temperature are the same as each other. Therefore, damage to the fan motor  157  may be prevented using the intake air temperature without using an external air temperature sensor. 
         [0059]    The controller  110  confirms the intake air temperature (S 225 ) when the ignition-off time exceeds the decision-possible time. Here, the intake air temperature may be a temperature measured through the intake air temperature measurer when the ignition of the vehicle is turned off. 
         [0060]    The controller  110  decides whether or not the intake air temperature is present within a predetermined temperature (S 230 ). That is, the controller  110  may decide whether or not the intake air temperature is less than or equal to a maximum temperature, and greater than or equal to a minimum temperature. Here, the maximum temperature and the minimum temperature indicate reference temperatures for deciding a temperature at which the cooling fan  160  may be frozen, and may be set by a worker or be set through a predefined algorithm (for example, a program or a probability model). For example, the maximum temperature may be 7° C., and the minimum temperature may be −10° C. 
         [0061]    The controller  110  decides whether or not the compressor  125  is operated (S 235 ) when the intake air temperature is present within the predetermined temperature. That is, the controller  110  may decide whether the compressor  125  is in a turn-on state or a turn-off state when the intake air temperature is greater than or equal to the minimum temperature and is less than or equal to the maximum temperature. 
         [0062]    The controller  110  decides whether or not a vehicle speed is 0 (S 240 ) when the compressor  125  is operated. That is, the controller  110  confirms the vehicle speed provided from the speed measurer when the compressor  125  is operated. The controller  110  decides whether or not the vehicle speed is 0 to decide whether or not the vehicle is in an idle state. In addition, the controller  110  generates an operation signal for operating the cooling fan  160  when the vehicle speed is 0. Here, the operation signal may be a low speed operation signal for operating the cooling fan  160  at a low speed. 
         [0063]    The controller  110  performs locking detection for whether to lock or normally operate the fan motor  157  (S 245 ). A method for detecting locking of the fan motor will be described in detail with reference to  FIG. 4 . 
         [0064]    The controller  110  decides whether or not a locking detection result is normal (S 250 ). 
         [0065]    The controller  110  stops an operation of the cooling fan  160  (S 255 ) when the locking detection result is not normal. That is, the controller  110  stops the operation of the cooling fan  160  and stops an operation of the compressor  125  when the locking detection result is locking. 
         [0066]    Meanwhile, the controller  110  moves to S 275  to operate the cooling fan  160 , when the locking detection result is normal. Here, since a method for controlling the cooling fan  160  that is normal is the same as or similar to a method for controlling the cooling fan  160  that is generally used, a detailed description therefor will be omitted. 
         [0067]    The controller  110  confirms whether or not the ignition is turned off (S 260 ). That is, the controller  110  may complete the control of the cooling fan when the ignition is turned off. 
         [0068]    Meanwhile, the controller  110  confirms the immediately previous state of the cooling fan (S 265 ) when the ignition-off time is less than or equal to the decision-possible time. That is, since the controller  110  may decide that the vehicle is not parked in the night when the ignition-off time is less than or equal to the decision-possible time, a state of the cooling fan  160  that was decided by previously turning on the ignition is confirmed. 
         [0069]    The controller  110  decides whether or not the immediately previous state of the cooling fan is normal (S 270 ). 
         [0070]    The controller  110  operates the cooling fan  160  (S 275 ) when the immediately previous state of the cooling fan is normal. In addition, the controller  110  may normally drive the cooling fan  160  since it is not severe cold when the intake air temperature exceeds the maximum temperature. Then, the controller  110  may confirm that the ignition is turned off. 
         [0071]    Meanwhile, the controller  110  turns off the compressor  125  (S 280 ) when the intake air temperature is less than the minimum temperature. 
         [0072]    The controller  110  turns off the air conditioner switch  120  (S 285 ) when the compressor  125  is not operated as a confirmation result in S 235 , the vehicle speed is not 0 as a decision result in S 240 , or the controller  110  turns off the compressor  125  in S 280 . 
         [0073]    The controller  110  confirms a coolant temperature (S 290 ). That is, the controller  110  receives the coolant temperature provided from the coolant temperature measurer  108  in order to control the cooling fan  160  and confirms the received coolant temperature, when the air conditioner switch  120  is turned off. The controller  110  decides whether or not the coolant temperature is greater than or equal to a reference temperature. 
         [0074]    The controller  110  operates the cooling fan  160  (S 295 ) when the coolant temperature is greater than or equal to the reference temperature. That is, the controller  110  may lower a temperature of the engine by operating the cooling fan  160  when the coolant temperature is greater than or equal to the reference temperature, in order to prevent overheat of the engine. Here, the reference temperature indicates a reference temperature for deciding whether or not the overheat is generated in the engine, and may be a predetermined value. For example, as shown in  FIG. 3 , the reference temperature  310  may be 105° C. 
         [0075]    The controller  110  provides the operation signal to the fan motor  157  through the relay  130  and the connector  140 , and operates the cooling fan  160  through the fan motor  157 . Here, the operation signal is a high speed operation signal  320 . Therefore, the cooling fan  160  is operated at a high speed, thereby making it possible to lower the temperature of the engine. 
         [0076]      FIG. 4  is a flow chart showing a method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention,  FIG. 5  is an illustrative view for describing the method for detecting locking in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention, and  FIG. 6  is an illustrative view for describing a first change rate and a second change rate in the method for controlling the cooling fan of the vehicle according to an exemplary embodiment of the present invention. 
         [0077]    Referring to  FIGS. 4 to 6 , the controller  110  confirms a first change rate of the air conditioner refrigerant pressure for a first measurement time (S 410 ). Here, the first measurement time may indicate a time delayed when the operation signal is transmitted from the controller  110  to the fan motor  157  through the relay  130  and the connector  140 . The reason for delaying and then transmitting the operation signal in the controller  110  as described above is to prevent bugs from being generated in the relay  130 , the connector  140 , and the like. Here, as shown in  FIG. 5 , the first measurement time  510  may be a time from 0 second to a first time. For example, the first time may be 0.5 second. 
         [0078]    In other words, the controller  110  receives a first air conditioner refrigerant pressure provided from the pressure measurer  106  at 0 second, and receives a second air conditioner refrigerant pressure provided from the pressure measurer  106  at the first time. The controller  110  calculates the first change rate on the basis of the first air conditioner refrigerant pressure and the second air conditioner refrigerant pressure. Here, the first change rate may be represented by a gradient  610 , as shown in  FIG. 6 . 
         [0079]    The controller  110  operates the cooling fan  160  for a second measurement time (S 420 ). In other words, the controller  110  provides the operation signal to the relay  130  at the first time, and the relay  130  provides the operation signal to the connector  140 . Here, the operation signal may be a low speed operation signal. The low speed connector  146  of the connector  140  drives the fan motor  157  through the resistor  153  when the low speed operation signal is received. Therefore, the cooling fan  160  may be operated by the fan motor  157 . 
         [0080]    Here, as shown in  FIG. 5 , the second measurement time  530  may indicate a time for which the cooling fan  160  is operated, and may be a predetermined value. The second measurement time  530  may be a time from the first time to a second time. For example, the second time may be 3.5 seconds. 
         [0081]    The controller  110  stops the operation of the cooling fan  160  at the second time(S 430 ). 
         [0082]    The controller  110  confirms a second change rate of the air conditioner refrigerant pressure for the second measurement time (S 440 ). In other words, the controller  110  receives a third air conditioner refrigerant pressure provided from the pressure measurer  106  at the first time, and receives a fourth air conditioner refrigerant pressure provided from the pressure measurer  106  at the second time. The controller  110  calculates the second change rate on the basis of the third air conditioner refrigerant pressure and the fourth air conditioner refrigerant pressure. Here, the second change rate may be represented by a gradient  630 , as shown in  FIG. 6 . 
         [0083]    The controller  110  decides whether or not a total measurement time exceeds a reference time (S 450 ). That is, the controller  110  adds the first measurement time and the second measurement time to each other to generate the total measurement time, and decides whether or not the total measurement time exceeds the reference time. 
         [0084]    The controller  110  decides whether or not a comparison value is less than or equal to a decision reference (S 460 ). In detail, the controller  110  calculates the comparison value on the basis of the first change rate and the second change rate. That is, the controller  110  may calculate the comparison value through equation 1. 
         [0000]        C=B/A   [equation 1]
 
         [0085]    Here, C may indicate the comparison value, A may indicate the first change rate, and B may indicate the second change rate. 
         [0086]    The controller  110  decides whether or not the comparison value is less than or equal to the decision reference (S 460 ). Here, the decision reference is a reference value for deciding whether to normally operate the fan motor  157  or lock the fan motor  157 . For example, the decision reference may be 0.7. 
         [0087]    The controller  110  decides whether or not the comparison value is maintained for a duration in a state in which the comparison value is less than or equal to the decision reference (S 470 ). For example, the duration may be 2 seconds. 
         [0088]    The controller  110  decides that the cooling fan  160  is normal (S 480 ) when the comparison value is maintained for the duration in the state in which the comparison value is less than or equal to the decision reference. 
         [0089]    The controller  110  decides that the fan motor  157  is locked (S 490 ) in the case in which the comparison value exceeds the decision reference or the comparison value is not maintained for the duration in the state in which the comparison value is less than or equal to the decision reference. 
         [0090]    As described above, the apparatus  50  for controlling a cooling fan of a vehicle according to an exemplary embodiment of the present invention decides whether or not cold weather conditions (e.g., winter) are present on the basis of the intake air temperature of air introduced from the outside into the vehicle when the ignition-off time exceeds the decision-possible time. In cold weather conditions, the apparatus  50  for controlling the cooling fan confirms the change rate of the air conditioner refrigerant pressure to lock the fan motor  157 , thereby making it possible to prevent damage to the fan motor. 
         [0091]    While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.