A sliding door for a motor vehicle includes a sliding door arrester to prevent the sliding door from inadvertently closing during a deceleration event. The sliding door arrestor includes a base fixed relative to a guide rail and a locking element pivotally attached to the base. The locking element includes a mass and a lock. The locking element rotates relative to the base during a deceleration event to engage the lock with a biasing member to prevent movement of a sliding element that is displaceable along the guide rail.