Cooler passivation process for a coolant cooler of a cooler device mounted in a motor vehicle, cooler device, and use of a motor vehicle to passivate a coolant cooler of a cooler device

A cooler passivation method for a coolant cooler of a cooler device mounted in a motor vehicle, comprising:

• 1) providing the cooler device with the coolant cooler, which comprises at least one aluminium cooling channel with a cooler surface provided with flux;
• 2) providing the cooler device in the motor vehicle;
• 3) starting up the cooler device and a fuel cell of the motor vehicle, and starting up the motor vehicle;
• 4) providing an aqueous passivation solution from a passivation layer forming material provided on the cooler device and fuel cell wastewater, which, during the operation of the fuel cell, is provided as reaction product of the same;
• 5) applying the aqueous passivation solution to the cooler surface of the at least one aluminium cooling channel provided with the flux, so that the aqueous passivation solution reacts with the cooler surface of the at least one aluminium cooling channel provided with the flux under the supply of heat energy provided by the coolant cooler to form a passivation layer.