In this paper, we analyze the impact of a (small) heterogeneity of jump type on the most simple localized solutions of a three-component FitzHugh-Nagumo-type system. We show that the heterogeneity can pin a 1-front solution, which travels with constant (non-zero) speed in the homogeneous setting, to a fixed, explicitly determined, distance from the heterogeneity. Moreover, we establish the stability of this heterogeneous pinned 1-front solution. In addition, we analyze the pinning of 1-pulse, or 2-front, solutions. The paper is concluded with simulations in which we consider the dynamics and interactions of N -front patterns in domains with M heterogeneities of jump type (N = 3, 4, M ≥ 1).