What is the test for an appeal without a probable cause certificate?

The law recognizes an exception to the certificate requirement of section 1237.5. This exception, stated in the second paragraph of rule 31(d), permits an appeal without a probable cause certificate if the appeal "is based solely upon grounds (1) occurring after entry of the plea which do not challenge its validity or (2) involving a search or seizure, the validity of which was contested pursuant to section 1538.5 of the Penal Code." It further provides, that "the appeal shall not be operative unless the notice of appeal states that it is based upon such grounds." (See People v. Mendez, supra, 19 Cal.4th at p. 1096; People v. Lloyd, supra, 17 Cal.4th at p. 664.)⁴