Cal. VEH § 40515

(a) When a person signs a written promise to appear or is granted a continuance of his or her promise to appear at the time and place specified in the written promise to appear or the continuance thereof, and has not posted full bail or has failed to pay an installment of bail as agreed to under Section 40510.5, the magistrate may issue and have delivered for execution a warrant for his or her arrest within 20 days after his or her failure to appear before the magistrate or pay an installment of bail as agreed, or if the person promises to appear before an officer authorized to accept bail other than a magistrate and fails to do so on or before the date on which he or she promised to appear, then, within 20 days after the delivery of the written promise to appear by the officer to a magistrate having jurisdiction over the offense.

(b) When the person violates his or her promise to appear before an officer authorized to receive bail other than a magistrate, the officer shall immediately deliver to a magistrate having jurisdiction over the offense charged the written promise to appear and the complaint, if any, filed by the arresting officer.