A new method for computing minimum distances, based on the ability of the soft-in decoder (if it exists) to overcome error impulse patterns, was recently proposed. This error impulse method, which delivers the results in record time, makes it possible to easily predict the asymptotic behaviour of the code considered. In this paper, we address the association of a turbo code and an M-PSK modulation, with the so-called pragmatic or bit-interleaved coded modulation (BICM) approach, and we develop a rationale to enable the performance prediction of such a coded scheme.