Cal. Gov. Code § 1775
Whenever there is a vacancy in the office of the Superintendent of Public Instruction, the Lieutenant Governor, Secretary of State, Controller, Treasurer, or Attorney General, or on the State Board of Equalization, the Governor shall nominate a person to fill the vacancy who shall take office upon confirmation by a majority of the membership of the Senate and a majority of the membership of the Assembly and who shall hold office for the balance of the unexpired term. In the event the nominee is neither confirmed nor refused confirmation by both the Senate and the Assembly within 90 days of the submission of the nomination, the nominee shall take office as if he or she had been confirmed by a majority of the Senate and Assembly; provided, that if such 90-day period ends during a recess of the Legislature, the period shall be extended until the sixth day following the day on which the Legislature reconvenes.
After a vacancy has occurred in an office specified in this section and prior to the time such vacancy is filled as provided in this section, the chief deputy to the above constitutional officers shall discharge the duties of the office.
Ca. Gov. Code § 1775