@@ -197,28 +197,13 @@ def test_future_altaz():
     location = EarthLocation(lat=0 * u.deg, lon=0 * u.deg)
     t = Time("J2161")
 
-    # check that these message(s) appear among any other warnings.  If tests are run with
-    # --remote-data then the IERS table will be an instance of IERS_Auto which is
-    # assured of being "fresh".  In this case getting times outside the range of the
-    # table does not raise an exception.  Only if using IERS_B (which happens without
-    # --remote-data, i.e. for all CI testing) do we expect another warning.
+    # check that these message(s) appear among any other warnings
     if PYTEST_LT_8_0:
-        ctx1 = ctx2 = nullcontext()
+        ctx1 = nullcontext()
     else:
         ctx1 = pytest.warns(erfa.core.ErfaWarning)
-        ctx2 = pytest.warns(AstropyWarning, match=".*times are outside of range.*")
-    with (
-        ctx1,
-        ctx2,
-        pytest.warns(
-            AstropyWarning,
-            match="Tried to get polar motions for times after IERS data is valid.*",
-        ) as found_warnings,
-    ):
+    with ctx1, pytest.warns(
+        AstropyWarning,
+        match="Tried to get polar motions for times after IERS data is valid.*",
+    ) as found_warnings:
         SkyCoord(1 * u.deg, 2 * u.deg).transform_to(AltAz(location=location, obstime=t))
-
-    if isinstance(iers.earth_orientation_table.get(), iers.IERS_B):
-        assert any(
-            "(some) times are outside of range covered by IERS table." in str(w.message)
-            for w in found_warnings
-        )
@@ -165,9 +165,9 @@ class Conf(_config.ConfigNamespace):
 
     auto_download = _config.ConfigItem(
         True,
-        "Enable auto-downloading of the latest IERS data.  If set to False "
-        "then the local IERS-B file will be used by default (even if the "
-        "full IERS file with predictions was already downloaded and cached). "
+        "Enable auto-downloading of the latest IERS-A data.  If set to False "
+        "then the bundled IERS-A file will be used by default (even if a "
+        "newer version of the IERS-A file was already downloaded and cached). "
         "This parameter also controls whether internet resources will be "
         "queried to update the leap second table if the installed version is "
         "out of date. Default is True.",
@@ -545,9 +545,9 @@ class IERS_A(IERS):
 
     Notes
     -----
-    The IERS A file is not part of astropy.  It can be downloaded from
-    ``iers.IERS_A_URL`` or ``iers.IERS_A_URL_MIRROR``. See ``iers.__doc__``
-    for instructions on use in ``Time``, etc.
+    If the package IERS A file (```iers.IERS_A_FILE``) is out of date, a new
+    version can be downloaded from ``iers.IERS_A_URL`` or ``iers.IERS_A_URL_MIRROR``.
+    See ``iers.__doc__`` for instructions on use in ``Time``, etc.
     """
 
     iers_table = None
@@ -758,6 +758,10 @@ class IERS_Auto(IERS_A):
     """
     Provide most-recent IERS data and automatically handle downloading
     of updated values as necessary.
+
+    The returned table combines the IERS-A and IERS-B files, with the data
+    in the IERS-B file considered to be official values and thus superseding
+    values from th IERS-A file at the same times.
     """
 
     iers_table = None
@@ -772,8 +776,8 @@ def open(cls):
         (or non-existent) then it will be downloaded over the network and cached.
 
         If the configuration setting ``astropy.utils.iers.conf.auto_download``
-        is set to False then ``astropy.utils.iers.IERS()`` is returned.  This
-        is normally the IERS-B table that is supplied with astropy.
+        is set to False then the bundled IERS-A table will be used rather than
+        any downloaded version of the IERS-A table.
 
         On the first call in a session, the table will be memoized (in the
         ``iers_table`` class attribute), and further calls to ``open`` will
@@ -786,7 +790,7 @@ def open(cls):
 
         """
         if not conf.auto_download:
-            cls.iers_table = IERS_B.open()
+            cls.iers_table = cls.read()
             return cls.iers_table
 
         all_urls = (conf.iers_auto_url, conf.iers_auto_url_mirror)
@@ -817,8 +821,8 @@ def open(cls):
             # Issue a warning here, perhaps user is offline.  An exception
             # will be raised downstream if actually trying to interpolate
             # predictive values.
-            warn("unable to download valid IERS file, using local IERS-B", IERSWarning)
-            cls.iers_table = IERS_B.open()
+            warn("unable to download valid IERS file, using local IERS-A", IERSWarning)
+            cls.iers_table = cls.read()
 
         return cls.iers_table
 
@@ -932,7 +936,7 @@ def _substitute_iers_b(cls, table):
         IERS-A has IERS-B values included, but for reasons unknown these
         do not match the latest IERS-B values (see comments in #4436).
         Here, we use the bundled astropy IERS-B table to overwrite the values
-        in the downloaded IERS-A table.
+        in the IERS-A table.
         """
         iers_b = IERS_B.open()
         # Substitute IERS-B values for existing B values in IERS-A table
 
@@ -25,27 +25,9 @@
 
 FILE_NOT_FOUND_ERROR = getattr(__builtins__, "FileNotFoundError", OSError)
 
-try:
-    iers.IERS_A.open("finals2000A.all")  # check if IERS_A is available
-except OSError:
-    HAS_IERS_A = False
-else:
-    HAS_IERS_A = True
-
 IERS_A_EXCERPT = get_pkg_data_filename(os.path.join("data", "iers_a_excerpt"))
 
 
-def setup_module():
-    # Need auto_download so that IERS_B won't be loaded and cause tests to
-    # fail. Files to be downloaded are handled appropriately in the tests.
-    iers.conf.auto_download = True
-
-
-def teardown_module():
-    # This setting is to be consistent with astropy/conftest.py
-    iers.conf.auto_download = False
-
-
 class TestBasic:
     """Basic tests that IERS_B returns correct values"""
 
@@ -216,7 +198,6 @@ def test_simple(self):
         assert len(iers_tab[:2]) == 2
 
 
-@pytest.mark.skipif(not HAS_IERS_A, reason="requires IERS_A")
 class TestIERS_A:
     @classmethod
     def teardown_class(self):
@@ -261,6 +242,14 @@ def setup_class(self):
         self.iers_a_url_2 = Path(self.iers_a_file_2).as_uri()
         self.t = Time.now() + TimeDelta(10, format="jd") * np.arange(self.N)
 
+        # This group of tests requires auto downloading to be on
+        iers.conf.auto_download = True
+
+        # auto_download = False is tested in test_IERS_B_parameters_loading_into_IERS_Auto()
+
+    def teardown_class(self):
+        iers.conf.auto_download = False
+
     def teardown_method(self, method):
         """Run this after every test."""
         iers.IERS_Auto.close()
@@ -310,12 +299,6 @@ def test_auto_max_age_minimum(self):
                     iers_table = iers.IERS_Auto.open()
                     _ = iers_table.ut1_utc(self.t.jd1, self.t.jd2)
 
-    def test_no_auto_download(self):
-        with iers.conf.set_temp("auto_download", False):
-            t = iers.IERS_Auto.open()
-        assert type(t) is iers.IERS_B
-
-    @pytest.mark.remote_data
     def test_simple(self):
         with iers.conf.set_temp("iers_auto_url", self.iers_a_url_1):
             dat = iers.IERS_Auto.open()
@@ -383,8 +366,10 @@ def test_simple(self):
             assert dat["MJD"][-1] == (57539.0 + 60) * u.d
 
 
-@pytest.mark.remote_data
 def test_IERS_B_parameters_loading_into_IERS_Auto():
+    # Double-check that auto downloading is off
+    assert not iers.conf.auto_download
+
     A = iers.IERS_Auto.open()
     B = iers.IERS_B.open()
 
@@ -448,35 +433,31 @@ def test_iers_b_dl():
         iers.IERS_B.close()
 
 
-@pytest.mark.remote_data
-def test_iers_out_of_range_handling(tmp_path):
-    # Make sure we don't have IERS-A data available anywhere
-    with set_temp_cache(tmp_path):
-        iers.IERS_A.close()
-        iers.IERS_Auto.close()
-        iers.IERS.close()
+def test_iers_b_out_of_range_handling():
+    # The following error/warning applies only to IERS_B, not to the default IERS_Auto
+    with iers.earth_orientation_table.set(iers.IERS_B.open()):
         now = Time.now()
-        with iers.conf.set_temp("auto_download", False):
-            # Should be fine with built-in IERS_B
-            (now - 300 * u.day).ut1
 
-            # Default is to raise an error
-            match = r"\(some\) times are outside of range covered by IERS table"
-            with pytest.raises(iers.IERSRangeError, match=match):
-                (now + 100 * u.day).ut1
+        # Should be fine with bundled IERS-B
+        (now - 300 * u.day).ut1
 
-            with iers.conf.set_temp("iers_degraded_accuracy", "warn"):
-                with pytest.warns(iers.IERSDegradedAccuracyWarning, match=match):
-                    (now + 100 * u.day).ut1
+        # Default is to raise an error
+        match = r"\(some\) times are outside of range covered by IERS table"
+        with pytest.raises(iers.IERSRangeError, match=match):
+            (now + 100 * u.day).ut1
 
-            with iers.conf.set_temp("iers_degraded_accuracy", "ignore"):
+        with iers.conf.set_temp("iers_degraded_accuracy", "warn"):
+            with pytest.warns(iers.IERSDegradedAccuracyWarning, match=match):
                 (now + 100 * u.day).ut1
 
+        with iers.conf.set_temp("iers_degraded_accuracy", "ignore"):
+            (now + 100 * u.day).ut1
+
 
 @pytest.mark.remote_data
 def test_iers_download_error_handling(tmp_path):
-    # Make sure we don't have IERS-A data available anywhere
-    with set_temp_cache(tmp_path):
+    # Make sure an IERS-A table isn't already loaded
+    with set_temp_cache(tmp_path), iers.conf.set_temp("auto_download", True):
         iers.IERS_A.close()
         iers.IERS_Auto.close()
         iers.IERS.close()
@@ -488,7 +469,7 @@ def test_iers_download_error_handling(tmp_path):
             with iers.conf.set_temp("iers_auto_url_mirror", "https://google.com"):
                 with pytest.warns(iers.IERSWarning) as record:
                     with iers.conf.set_temp("iers_degraded_accuracy", "ignore"):
-                        (now + 100 * u.day).ut1
+                        (now + 400 * u.day).ut1
 
                 assert len(record) == 3
                 assert str(record[0].message).startswith(
@@ -498,7 +479,7 @@ def test_iers_download_error_handling(tmp_path):
                     "malformed IERS table from https://google.com"
                 )
                 assert str(record[2].message).startswith(
-                    "unable to download valid IERS file, using local IERS-B"
+                    "unable to download valid IERS file, using local IERS-A"
                 )
 
 
 
@@ -0,0 +1 @@
+The return type of ``IERS_Auto.open()`` is no longer ``IERS_B`` when automatic updating of the IERS-A file is disabled or the downloading of the new file fails.
@@ -0,0 +1 @@
+Fixed the unintended behavior where the IERS-A file bundled in ``astropy-iers-data`` would be ignored if automatic updating of the IERS-A file were disabled or if downloading the new file failed.
@@ -94,9 +94,9 @@ that relate to automatic IERS downloading. Four of the most
 important to consider are the following:
 
   auto_download:
-    Enable auto-downloading of the latest IERS data.  If set to ``False`` then
-    the local IERS-A and IERS-B files will be used by default (even if the full
-    IERS file with predictions was already downloaded and cached).  This
+    Enable auto-downloading of the latest IERS-A data.  If set to ``False`` then
+    the bundled IERS-A file will be used by default (even if a newer
+    versions of the IERS-A file was already downloaded and cached).  This
     parameter also controls whether internet resources will be queried to update
     the leap second table if the installed version is out of date.
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+The return type of ``IERS_Auto.open()`` is no longer ``IERS_B`` when automatic updating of the IERS-A file is disabled or the downloading of the new file fails.
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Fixed the unintended behavior where the IERS-A file bundled in ``astropy-iers-data`` would be ignored if automatic updating of the IERS-A file were disabled or if downloading the new file failed.