Cal. Vehicle Code § 4000.17

(a) For purposes of this section, “heavy-duty vehicle” means a nongasoline heavy-duty onroad motor vehicle with a gross vehicle weight rating of more than 14,000 pounds, as defined by the State Air Resources Board pursuant to Section 44152 of the Health and Safety Code. (b) No later than one year after the effective date of a regulation implementing the Heavy-Duty Vehicle Inspection and Maintenance Program (Chapter 5.5 (commencing with Section 44150) of Part 5 of Division 26 of the Health and Safety Code), the department shall confirm prior to the initial registration, the transfer of ownership, or the renewal of registration that a heavy-duty vehicle is compliant with, or exempt from, the Heavy-Duty Vehicle Inspection and Maintenance Program. (c) Subdivision (b) does not apply to a transfer of ownership and registration under any of the following circumstances: (1) A motor vehicle registered to a sole proprietorship is transferred to the proprietor as owner. (2) The transfer is between companies the principal business of which is leasing motor vehicles, if there is no change in the lessee or operator of the motor vehicle or between the lessor and the person who has been, for at least one year, the lessee’s operator of the motor vehicle. (3) The transfer is between the lessor and lessee of the motor vehicle, if there is no change in the lessee or operator of the motor vehicle. (4) An additional individual is added as a registered owner of the motor vehicle. (d) The State Air Resources Board shall notify the department of the motor vehicles allowed to be registered pursuant to this section.