No - if you file Federal Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return, you do not need to file a separate California extension. However, the extension to file does not mean an extension to pay: if you owe any California income tax liability and are unable to file your return, you need to pay any tax due to the California Franchise Tax Board using Form FTB 3519, Payment Voucher for Automatic Extension for Individuals.
For more information, please see the following web page from the California Tax Service Center:
http://www.taxes.ca.gov/income_tax/extind.shtml
