It was also by his advice that the commander-in-chief, Jean-Baptiste Jourdan, discovered Josias, Prince of Coburg's unfortunate position behind the Wattignies forest, compelled him to retreat across the Sambre and subsequently lifted the siege of Maubeuge: Ernouf's part in this action, the Battle of Hondschoote, earned him his promotion to Major General on 23 "frimaire an II" (13 December 1793). When Jourdan did not order an aggressive pursuit, both he and Ernouf were recalled by the Committee of Public Safety in disgrace. He was suspended on suspicion of being a counter-revolutionary, but reinstated upon the end of the Reign of Terror in 1795. Upon his reinstatement, he was appointed Chief of Staff of the Army of the Moselle and the Army of Sambre-et-Meuse. He held several administrative posts, including a stint in which he helped to develop the topographical and geographical military maps.