The Model Based System Engineering (MBSE) is based on simplified mathematical models that reflects the dynamic behavior of the systems. These latter are most of time nonlinear and need control schemes taking in consideration exogenous perturbations. The main contribution of this paper is the design of a robust passivity based sliding mode control scheme for a 1.26 KW PEMFC. The uncertainties considered in this paper are temperature and load variation. The FC reference current is adapted in a linear transformation by introducing a temperature sensor. This information is present in most of commercial PEMFC and not used in the closed-loop system. Moreover, the proposed approach cancels the errors caused by the average approach modeling and the observer (the part which replaces current sensor). Robustness against load variation is assured via a proportional integral compensation of the incremental value of load resistance. The performance of the controller and the effectiveness of our approach is shown through the simulation with MATLAB-SIMULINK software.