A position adjustment device for a vehicle seat, comprising: a. two slideways extending along a longitudinal axis (X), each slideway comprising a fixed profile and a movable profile , each slideway comprising a mechanism for adjusting the position of the movable profile relative to the fixed profile along the longitudinal axis (X), the adjustment mechanism being configured to cooperate with an electric motor , b. a crossmember fixed to the respective movable profiles of the two slideways , c. an electric motor configured to drive each of the adjustment mechanisms via a transmission link , the electric motor being fixed to the crossmember , d. an electronic control unit configured to control the electric motor , wherein the electronic control unit is fixed to the crossmember , characterized in that the crossmember comprises a housing for receiving the electric motor, the receiving housing comprising a bottom wall and two side walls , wherein a side wall is arranged between the electric motor and the electronic control unit , in that the electronic control unit is arranged against an outer surface of a side wall of the housing for receiving the electric motor , and in that the crossmember comprises guide elements configured to guide the electronic control unit during the connection of the electronic control unit to the electric motor . a. two slideways extending along a longitudinal axis (X), each slideway comprising a fixed profile and a movable profile , each slideway comprising a mechanism for adjusting the position of the movable profile relative to the fixed profile along the longitudinal axis (X), the adjustment mechanism being configured to cooperate with an electric motor , b. a crossmember fixed to the respective movable profiles of the two slideways , c. an electric motor configured to drive each of the adjustment mechanisms via a transmission link , the electric motor being fixed to the crossmember , d. an electronic control unit configured to control the electric motor , wherein the electronic control unit is fixed to the crossmember , characterized in that the crossmember comprises a housing for receiving the electric motor, the receiving housing comprising a bottom wall and two side walls , wherein a side wall is arranged between the electric motor and the electronic control unit , in that the electronic control unit is arranged against an outer surface of a side wall of the housing for receiving the electric motor , and in that the crossmember comprises guide elements configured to guide the electronic control unit during the connection of the electronic control unit to the electric motor . the crossmember comprises a housing for receiving the electric motor, the receiving housing comprising a bottom wall and two side walls , wherein a side wall is arranged between the electric motor and the electronic control unit , in that the electronic control unit is arranged against an outer surface of a side wall of the housing for receiving the electric motor , and in that the crossmember comprises guide elements configured to guide the electronic control unit during the connection of the electronic control unit to the electric motor . <EOS>