In this work, we are interested in the small time local null controllability for the viscous Burgers’ equation yt − yxx + yyx = u(t) on the line segment [0, 1], with null boundary conditions. The second-hand side is a scalar control playing a role similar to that of a pressure. In this setting, the classical Lie bracket necessary condition [f1, [f1, f0]] introduced by Sussmann fails to conclude...