California Code of Civil Procedure Section 580(b) Applies To
Was the loan incurred in order to purchase real property as a residence ( 1-4 units) for the debtor AND the property was used to secure the purchase loan? Section 580(b) applies which states that "No deficiency judgment shall lie." If you have re-financed, this may impair your ability to use the anti deficiency statute.
California Code of Civil Procedure Section 580(b) DOES NOT Apply To
Vacation homes, equity lines of credit (HELOC), investment property (not debtor's residence), property with more than 4 unites. Therefore, if anti-deficiency statues DO apply, there may still be an issue of the equity line of credit (the second mortgage that you took out for a vacation, purchase another home, etc.). If you do decide to do a short sale, loan modification, or deed in lieu, consult a tax attorney about the tax consequences, especially regarding the cancellation of debt.