The invention relates to an attachment device (1) for a module for dispensing an aqueous solution contained in a tank on board a motor vehicle.
According to the invention, such an attachment device (1) comprises a pump stator (31), a heating means and a heat diffuser (14) which comprises a base (15) and a first plurality of walls (16) that are substantially vertical with respect to said base (15) and define at least one first internal volume (3, 17), said base (15) and/or at least one wall that is substantially vertical with respect to the base (15) comprising at least one means (18) for positioning the pump stator and/or a first means (19) for attaching the pump stator and/or at least one second means (20) for attaching the heating means, the pump stator (31) and heat diffuser (14) assembly being overmolded with a plastic material, the attachment device (1) comprising at least one first through-hole (21), preferably in the region of the base of the attachment device (1), suitable for discharging the aqueous solution pumped by the pump, and a second through-hole (22) suitable for supplying the pump with aqueous solution.