Method for producing a modular electrical plug connector arrangement for a controller in a motor vehicle, wherein the plug connector arrangement has: a module carrier, and at least one first plug module and one second plug module, wherein the first plug module and the second plug module are arranged next to one another on the module carrier, wherein both the first plug module and also the second plug module each have a plug housing collar (12, 14), which plug housing collars protrude in a direction away from the module carrier and are each formed for receiving an electrical plug connector, wherein both the first plug module and also the second plug module each have a plurality of contact elements which are arranged in a contact region within the respective plug housing collar (12, 14) and are formed for interacting with complementary mating contact elements of the respective electrical plug connector, wherein the method comprises the following steps: arranging in each case one of the plug modules (6, 8) in a recess in the module carrier and precisely positioning the plug module (6, 8) relative to the module carrier, pressing the plug module (6, 8) against the module carrier, characterized by: laser welding the plug module (6, 8) to the module carrier in a fastening region, wherein the module carrier and the plug modules (6, 8) are composed of different plastic materials, and wherein the laser used for the laser welding is a laser of which the laser beam is absorbed substantially more weakly in the material of one of the two components selected from the group consisting of the module carrier and the plug modules (6, 8) than in the material of the other component, and wherein the laser beam is directed through the more weakly absorbing component to the more strongly absorbing component in the fastening region. a module carrier, and at least one first plug module and one second plug module, wherein the first plug module and the second plug module are arranged next to one another on the module carrier, wherein both the first plug module and also the second plug module each have a plug housing collar (12, 14), which plug housing collars protrude in a direction away from the module carrier and are each formed for receiving an electrical plug connector, wherein both the first plug module and also the second plug module each have a plurality of contact elements which are arranged in a contact region within the respective plug housing collar (12, 14) and are formed for interacting with complementary mating contact elements of the respective electrical plug connector, wherein the method comprises the following steps: arranging in each case one of the plug modules (6, 8) in a recess in the module carrier and precisely positioning the plug module (6, 8) relative to the module carrier, pressing the plug module (6, 8) against the module carrier, characterized by: laser welding the plug module (6, 8) to the module carrier in a fastening region, wherein the module carrier and the plug modules (6, 8) are composed of different plastic materials, and wherein the laser used for the laser welding is a laser of which the laser beam is absorbed substantially more weakly in the material of one of the two components selected from the group consisting of the module carrier and the plug modules (6, 8) than in the material of the other component, and wherein the laser beam is directed through the more weakly absorbing component to the more strongly absorbing component in the fastening region. arranging in each case one of the plug modules (6, 8) in a recess in the module carrier and precisely positioning the plug module (6, 8) relative to the module carrier, pressing the plug module (6, 8) against the module carrier, characterized by: laser welding the plug module (6, 8) to the module carrier in a fastening region, wherein the module carrier and the plug modules (6, 8) are composed of different plastic materials, and wherein the laser used for the laser welding is a laser of which the laser beam is absorbed substantially more weakly in the material of one of the two components selected from the group consisting of the module carrier and the plug modules (6, 8) than in the material of the other component, and wherein the laser beam is directed through the more weakly absorbing component to the more strongly absorbing component in the fastening region. laser welding the plug module (6, 8) to the module carrier in a fastening region, wherein the module carrier and the plug modules (6, 8) are composed of different plastic materials, and wherein the laser used for the laser welding is a laser of which the laser beam is absorbed substantially more weakly in the material of one of the two components selected from the group consisting of the module carrier and the plug modules (6, 8) than in the material of the other component, and wherein the laser beam is directed through the more weakly absorbing component to the more strongly absorbing component in the fastening region.