Mich. Comp. Laws § 600.8711

Sec. 8711. If an authorized local official issues a citation under section 8707, the court may accept an admission with explanation or an admission or denial of responsibility upon the citation without the necessity of a sworn complaint. If the defendant denies responsibility for the municipal civil infraction, further proceedings shall not be held until a sworn complaint is filed with the court. A warrant for arrest for failure to appear on the municipal civil infraction citation under section 8727(9) shall not be issued until a sworn complaint relative to the municipal civil infraction is filed with the court.