At the outbreak of World War II Jauer served as a staff officer and regimental commander. In April 1943 he was appointed commander the 20th Motorized Infantry and 20th Panzer Grenadier Division and took part in the Battle of the Kamenets-Podolsky pocket. He then led the 25th Panzer Division at the Battle of Kiev. On 12 March 1945 he took command of the 'Panzer Corps Großdeutschland' with which he surrendered.