California Code, Vehicle Code - VEH § 1803.3

(a) The clerk of any court that reverses a conviction for an offense described in subdivision (a) of Section 1803, which is not exempted under subdivision (b) of that section, shall prepare and forward to the department at its office in Sacramento an abstract of the record of the court covering the case in which the conviction was reversed.  In addition, if a court dismisses a charge of a violation of Section 40508 for which a notice was given to the department pursuant to former Section 40509 or former Section 40509.5, the court shall notify the department of the dismissal.

(b) The abstract shall be forwarded within 30 days of the date the judgment of reversal becomes final.  The notice of dismissal shall be given to the department not later than 30 days after the dismissal.  Within 30 days of receiving the abstract or notice, the department shall remove any record of that conviction, or notice received pursuant to former Section 40509 or former Section 40509.5, from the driver's record.

(c) As used in this section, “reverse” includes any action by which a conviction is nullified or set aside.