Method for determining a position of a sliding block, which is movably mounted along a sliding rail between a closed position and an open position, of a door drive, which has an arresting device, for automatically closing a door, wherein the arresting device comprises a blocking element for blocking a movement, which corresponds to a closing movement of the door, of the sliding block from the open position in the direction of the closed position and an energizable electromagnet; wherein the blocking element can be moved between an arresting position, in which it is designed to hamper the movement of the sliding block, and a release position, in which it is designed to release the movement of the sliding block; wherein the electromagnet, in a state in which it is energized with a specified current intensity, arrests the blocking element in the arresting position; and wherein the blocking element can be pushed from the arresting position to the release position by the sliding block when the sliding block passes across the blocking element; wherein the method comprises at least the following steps: applying a current of the specified current intensity or a current intensity lower than this to a magnet coil of the electromagnet; monitoring the coil current of the electromagnet; detecting the situation of the sliding block passing across the blocking element on the basis of the time course of the monitored coil current; and determining the position of the sliding block with respect to the blocking element, in particular whether the sliding block is in the open position or in the closed position, using the detection of the situation of the sliding block passing across the blocking element. wherein the blocking element can be moved between an arresting position, in which it is designed to hamper the movement of the sliding block, and a release position, in which it is designed to release the movement of the sliding block; wherein the electromagnet, in a state in which it is energized with a specified current intensity, arrests the blocking element in the arresting position; and wherein the blocking element can be pushed from the arresting position to the release position by the sliding block when the sliding block passes across the blocking element; wherein the method comprises at least the following steps: applying a current of the specified current intensity or a current intensity lower than this to a magnet coil of the electromagnet; monitoring the coil current of the electromagnet; detecting the situation of the sliding block passing across the blocking element on the basis of the time course of the monitored coil current; and determining the position of the sliding block with respect to the blocking element, in particular whether the sliding block is in the open position or in the closed position, using the detection of the situation of the sliding block passing across the blocking element. applying a current of the specified current intensity or a current intensity lower than this to a magnet coil of the electromagnet; monitoring the coil current of the electromagnet; detecting the situation of the sliding block passing across the blocking element on the basis of the time course of the monitored coil current; and determining the position of the sliding block with respect to the blocking element, in particular whether the sliding block is in the open position or in the closed position, using the detection of the situation of the sliding block passing across the blocking element.