Plug module comprising: a plug housing comprising: a connection piece which has a receiving region on an inner side; and comprising a sensor apparatus which is arranged in the receiving region of the connection piece, a cover which is connected to the connection piece by means of a fastening apparatus, wherein a plurality of straight, electrically conductive and spring-elastic contact pins are incorporated in the cover in such a way that respective first ends of the contact pins protrude into an inner volume of the plug housing and are arranged above the receiving region of the connection piece, and respective second ends of the contact pins are arranged in the region of a connection bushing of the cover, wherein the contact pins are arranged at a predetermined lateral distance parallel to one another, wherein the fastening apparatus is formed by a latching apparatus; wherein the latching apparatus has spring-elastic latching clips which are arranged on the cover and engage into associated latching lugs which are arranged on the connection piece, wherein the spring-elastic latching clips are arranged on an encircling edge which is formed on a side of the cover which faces the connection piece; and wherein the plurality of straight, spring-elastic contact pins which are arranged parallel to one another make direct contact with the respective electrical contact areas of the sensor apparatus; and wherein the plurality of contact pins are inserted into the cover in such a way that they are pressed against the respective electrical contacts of the sensor apparatus, wherein a temperature sensor is attached to the sensor apparatus, wherein the temperature sensor is formed by a heat conductor, wherein the temperature sensor is encapsulated by injection moulding with plastic, fitted in the connection piece and hot-caulked, wherein the temperature sensor has a plurality of electrically conductive contact clips which make contact with respective electrical contacts of the sensor apparatus. a connection piece which has a receiving region on an inner side; and comprising a sensor apparatus which is arranged in the receiving region of the connection piece, a cover which is connected to the connection piece by means of a fastening apparatus, wherein a plurality of straight, electrically conductive and spring-elastic contact pins are incorporated in the cover in such a way that respective first ends of the contact pins protrude into an inner volume of the plug housing and are arranged above the receiving region of the connection piece, and respective second ends of the contact pins are arranged in the region of a connection bushing of the cover, wherein the contact pins are arranged at a predetermined lateral distance parallel to one another, wherein the fastening apparatus is formed by a latching apparatus; wherein the latching apparatus has spring-elastic latching clips which are arranged on the cover and engage into associated latching lugs which are arranged on the connection piece, wherein the spring-elastic latching clips are arranged on an encircling edge which is formed on a side of the cover which faces the connection piece; and wherein the plurality of straight, spring-elastic contact pins which are arranged parallel to one another make direct contact with the respective electrical contact areas of the sensor apparatus; and wherein the plurality of contact pins are inserted into the cover in such a way that they are pressed against the respective electrical contacts of the sensor apparatus, wherein a temperature sensor is attached to the sensor apparatus, wherein the temperature sensor is formed by a heat conductor, wherein the temperature sensor is encapsulated by injection moulding with plastic, fitted in the connection piece and hot-caulked, wherein the temperature sensor has a plurality of electrically conductive contact clips which make contact with respective electrical contacts of the sensor apparatus.