A method for detecting a fault in a cooling circuit of a motor vehicle, the cooling circuit having, in the flow direction of a refrigerant, a compressor, a condenser, an expansion device and an evaporator, includes the following steps: measuring a first refrigerant pressure when the compressor is turned off; turning on the compressor; and is characterized by the steps: measuring a second refrigerant pressure after a certain time interval; forming a differential value from the second refrigerant pressure measured previously and the first refrigerant pressure; and comparing the differential value with at least one differential value for detecting a fault in the cooling circuit.