A lighting system for a motor vehicle comprising at least one primary optical device for emitting a light beam exhibiting a cutoff profile, the primary optical emission device comprising at least one light source and one single-piece primary optical member comprising an input surface suitable for receiving a light beam emitted by the light source, a ray interception surface configured to form the cutoff profile in the light beam received and an output surface for the light beam. This system also comprises a projection device arranged downstream of the primary optical emission device(s) and comprising an input surface arranged facing the primary optical emission device(s), and through which are introduced rays of the light beam derived as output from the primary optical emission device(s); a single continuous output surface through which the light beam is projected.