Cooler passivation process for coolant cooler of cooler device installed in motor vehicle, cooler device and use of motor vehicle for passivating coolant cooler of cooler device

The invention relates to a cooler passivation process for a coolant cooler (2) of a cooler device (1) installed in a motor vehicle. According to the cooler passivation process, a cooler arrangement (1) with a coolant cooler (2) having at least one aluminum cooling channel (3) with a cooler surface (4) provided with a flux is provided. The cooler device (1) is provided, for example installed in a motor vehicle, and then put into operation with at least one fuel cell of the motor vehicle. In order to form a passivation layer (8) on the coolant cooler (2), according to the invention, a previously provided aqueous passivation solution (5) formed from a passivation layer-forming material (6) and fuel cell wastewater (7) is applied to the cooler surface (4) of the at least one aluminum cooling channel (3) provided with the flux, the passivation solution (5) reacts with the cooler surface (4) of the at least one aluminum cooling channel (3) provided with the flux while supplying the thermal energy provided by the co