When can a defendant withdraw his plea and appeal against his sentence?

search and seizure issues for which an appeal is provided under section 1538.5, subdivision (m); and (2) issues regarding proceedings held subsequent to the plea for the purpose of determining the degree of the crime and the penalty to be imposed." (People v. Panizzon (1996) 13 Cal.4th 68, 74.)

As defendant conceded in his supplemental brief, the first exception does not apply to him because he did not obtain a ruling on his renewed motion to suppress, which would have preserved his right to appellate review. As to the remaining exception, "the critical inquiry is whether a challenge to the sentence is in substance a challenge to the validity of the plea, thus rendering the appeal subject to the requirements of section 1237.5." (People v. Panizzon, supra, 13 Cal.4th at p. 76.)

We have applied this test to a claim similar to defendant's claim here. In that case, the defendant argued that the trial court wrongly failed to grant him a continuance of his sentencing to allow him to determine whether the victim's recantation provided a basis to withdraw his plea. We held that the motion and the challenge to its denial were in substance attacks on the validity of the plea and a certificate of probable cause was necessary to pursue the appeal. (People v. Emery (2006) 140 Cal.App.4th 560, 564-565.)