Any person who operates, or any owner or farm labor contractor who knowingly allows the operation of, a farm labor vehicle in violation of subdivision (b) or (d) of Section 31401 or Section 31402 or 31403 is guilty of a misdemeanor. When a person has been convicted of willfully violating those provisions, the person shall, in addition, be fined not less than one thousand dollars ($1,000) for each violation, and no part of the fine may be suspended. If passengers are in the vehicle at the time of the violation, the person shall, in addition, be fined five hundred dollars ($500) for each passenger, not to exceed a total of five thousand dollars ($5,000) for each violation, and no part of this fine may be suspended. As used in this section, the terms “knowingly” and “willfully” have the same meaning as prescribed in Section 7 of the Penal Code.