California Code, Elections Code - ELEC § 19216

If a voting system or a part of a voting system has been certified or conditionally approved by the Secretary of State, it shall not be changed or modified until the Secretary of State has been notified in writing and has determined that the change or modification does not impair its accuracy and efficiency sufficient to require a reexamination and recertification, or conditional approval, pursuant to this article.  The Secretary of State may adopt rules and regulations governing the procedures to be followed in making his or her determination as to whether the change or modification impairs accuracy or efficiency.