The electrochemical behaviour of the cut-edge of hot-dipped aluminium–silicon-based alloy coated steel is studied in immersed conditions in sulphate and in chloride media. Preliminary studies performed on steel-pure Al bi-electrode demonstrate that a significant galvanic current can develop at short times (t<1000s) only in chloride solutions. In situ measurements of current density and pH distributions over cut-edge coated steels immersed in chloride solutions revealed a quasi-steady state current between the coating and the steel substrate, resulting from local (pitting like) dissolution of the aluminium–silicon-based alloy coating. In sulphate solutions, the coating is not at all sacrificial and remains passive.