The implementation of fuel cell systems in the automotive sector appears to be very promising in terms of sustainable energy usage and significant reduction of pollutant emissions. More specifically the development of the HT-PEM technology offers new advantageous methods for system design and integration within the different automotive applications. The concept of pure hydrogen driven HT-PEM fuel cell could lead to less complex configurations better adapted to the overall system. Since power density is still relatively little at ambient temperatures for todays HT-PEM fuel cell systems a preheating during start up is needed. In order to meet these requirements a modulating combustion system, with an integrated heat exchanger, based on combustion within inert porous media, was developed. The system is able to handle premixed combustion of 100 vol.% H₂, in the range of 5 to 10 kW, with a constant air ratio. The special concept of mixer eliminates the risk of flashback for the combustion process and enables operation with very low NO_x emissions. Besides the aforementioned characteristics, the combustion system is operated via CAN bus interface and the fuel / air control path could be produced by pneumatic combination.