diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 7a0a577ef1..6e74c2b460 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -53,11 +53,8 @@ class BaseDatabaseWrapper(object):
 
     __hash__ = object.__hash__
 
-    def _valid_connection(self):
-        return self.connection is not None
-
     def _cursor(self):
-        if not self._valid_connection():
+        if self.connection is None:
             conn_params = self.get_connection_params()
             self.connection = self.get_new_connection(conn_params)
             self.init_connection_state()
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index 754e876701..5a23dce095 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -402,15 +402,6 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         self.introspection = DatabaseIntrospection(self)
         self.validation = DatabaseValidation(self)
 
-    def _valid_connection(self):
-        if self.connection is not None:
-            try:
-                self.connection.ping()
-                return True
-            except DatabaseError:
-                self.close()
-        return False
-
     def get_connection_params(self):
         kwargs = {
             'conv': django_conversions,