SSRRS

Hi, Company has DB and DC (MP) Plans. They planned on making a db and DC contribution for the year ended 12/31/17. Inadvertently they deposited the DC contribution into the DB account (db plus dc contribution all went into db account, and was below DB Max). Can this be self corrected by transfering the money into the dc account? If yes, what if the transfer is made today, October 18th, as this is after 9/15?. Thank you