CA Veh Code Section 4000.6

A commercial motor vehicle, singly or in combination, that operates with a declared gross or combined gross vehicle weight that exceeds 10,000 pounds shall be registered pursuant to Section 9400.1.

(a)

A person submitting an application for registration of a commercial motor vehicle operated in combination with a semitrailer, trailer, or any combination thereof, shall include the declared combined gross weight of all units when applying for registration with the department, except as exempted under subdivision (a) of Section 9400.1.

(b)

This section does not apply to pickups nor to any commercial motor vehicle or combination that does not exceed 10,000 pounds gross vehicle weight.

(c)

A peace officer, as defined in Chapter 4.5 (commencing with Section 830) of Title 3 of Part 2 of the Penal Code, having reason to believe that a commercial motor vehicle is being operated, either singly or in combination, in excess of its registered declared gross or combined gross vehicle weight, may require the driver to stop and submit to an inspection or weighing of the vehicle or vehicles and an inspection of registration documents.

(d)

A person shall not operate a commercial motor vehicle, either singly or in combination, in excess of its registered declared gross or combined gross vehicle weight.

(e)

A violation of this section is an infraction punishable by a fine in an amount equal to the amount specified in Section 42030.1.