diff --git a/core/modules/auto_updates/auto_updates.install b/core/modules/auto_updates/auto_updates.install
index 6799a1c510..173d1ceaef 100644
--- a/core/modules/auto_updates/auto_updates.install
+++ b/core/modules/auto_updates/auto_updates.install
@@ -18,7 +18,7 @@ function auto_updates_requirements($phase) {
   }
 
   /** @var \Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManagerInterface $checker_manager */
-  $checker_manager = \Drupal::service('auto_updates.readiness_checker');
+  $checker_manager = \Drupal::service('auto_updates.readiness_checker_manager');
   if (!$checker_manager->isEnabled()) {
     return [];
   }
@@ -75,6 +75,6 @@ function auto_updates_requirements($phase) {
  */
 function auto_updates_install($is_syncing) {
   /** @var \Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManagerInterface $checker_manager */
-  $checker_manager = \Drupal::service('auto_updates.readiness_checker');
+  $checker_manager = \Drupal::service('auto_updates.readiness_checker_manager');
   $checker_manager->run();
 }
diff --git a/core/modules/auto_updates/auto_updates.module b/core/modules/auto_updates/auto_updates.module
index 7fec2f650f..70a68230aa 100644
--- a/core/modules/auto_updates/auto_updates.module
+++ b/core/modules/auto_updates/auto_updates.module
@@ -32,7 +32,7 @@ function auto_updates_page_top(array &$page_top) {
     if (in_array(\Drupal::routeMatch()->getRouteName(), $disabled_routes, TRUE)) {
       return;
     }
-    $last_check_timestamp = \Drupal::service('auto_updates.readiness_checker')->timestamp();
+    $last_check_timestamp = \Drupal::service('auto_updates.readiness_checker_manager')->timestamp();
     if (\Drupal::time()->getRequestTime() > $last_check_timestamp + ReadinessCheckerManagerInterface::LAST_CHECKED_WARNING) {
       $readiness_settings = Url::fromRoute('auto_updates.settings');
       \Drupal::messenger()->addError(t('Your site has not recently run an update readiness check. <a href=":url">Administer automatic updates</a> and run readiness checks manually.', [
@@ -40,7 +40,7 @@ function auto_updates_page_top(array &$page_top) {
       ]));
     }
     /** @var \Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManagerInterface $checker_manager */
-    $checker_manager = \Drupal::service('auto_updates.readiness_checker');
+    $checker_manager = \Drupal::service('auto_updates.readiness_checker_manager');
     $results = $checker_manager->getResults(ReadinessCheckerManagerInterface::ERROR);
     if ($results) {
       \Drupal::messenger()->addError(t('Your site is currently failing readiness checks for automatic updates. It cannot be <a href=":readiness_checks">automatically updated</a> until further action is performed:', [':readiness_checks' => 'https://www.drupal.org/docs/8/update/auto-updates#readiness-checks']));
@@ -64,7 +64,7 @@ function auto_updates_page_top(array &$page_top) {
 function auto_updates_cron() {
   $request_time = \Drupal::time()->getRequestTime();
   /** @var \Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManagerInterface $checker_manager */
-  $checker_manager = \Drupal::service('auto_updates.readiness_checker');
+  $checker_manager = \Drupal::service('auto_updates.readiness_checker_manager');
   $last_check = $checker_manager->timestamp();
   // Only allow cron to run once every hour.
   if ($last_check && ($request_time - $last_check) < 3600) {
@@ -72,7 +72,7 @@ function auto_updates_cron() {
   }
 
   /** @var \Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManagerInterface $checker_manager */
-  $checker_manager = \Drupal::service('auto_updates.readiness_checker');
+  $checker_manager = \Drupal::service('auto_updates.readiness_checker_manager');
   $checker_manager->run();
 }
 
@@ -81,7 +81,7 @@ function auto_updates_cron() {
  */
 function auto_updates_modules_installed($modules) {
   /** @var ReadinessCheckerManagerInterface $checker_manager */
-  $checker_manager = \Drupal::service('auto_updates.readiness_checker');
+  $checker_manager = \Drupal::service('auto_updates.readiness_checker_manager');
   if ($checker_manager->clearResultsStaleResults()) {
     $checker_manager->run();
   }
diff --git a/core/modules/auto_updates/auto_updates.routing.yml b/core/modules/auto_updates/auto_updates.routing.yml
index 1616bc5390..ce01cdf9f4 100644
--- a/core/modules/auto_updates/auto_updates.routing.yml
+++ b/core/modules/auto_updates/auto_updates.routing.yml
@@ -14,5 +14,6 @@ auto_updates.update_readiness:
     _title: 'Update readiness checking...'
   requirements:
     _permission: 'administer software updates'
+    _custom_access: '\Drupal\auto_updates\Controller\ReadinessCheckerController::access'
   options:
     _admin_route: TRUE
diff --git a/core/modules/auto_updates/auto_updates.services.yml b/core/modules/auto_updates/auto_updates.services.yml
index 0be04c9d2e..461fbcd4fb 100644
--- a/core/modules/auto_updates/auto_updates.services.yml
+++ b/core/modules/auto_updates/auto_updates.services.yml
@@ -4,7 +4,7 @@ services:
     arguments: ['%app.root%']
     tags:
       - { name: readiness_checker, category: error}
-  auto_updates.readiness_checker:
+  auto_updates.readiness_checker_manager:
     class: Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManager
     arguments: ['@keyvalue', '@config.factory']
     tags:
diff --git a/core/modules/auto_updates/src/Controller/ReadinessCheckerController.php b/core/modules/auto_updates/src/Controller/ReadinessCheckerController.php
index cd5ac996c5..27160de369 100644
--- a/core/modules/auto_updates/src/Controller/ReadinessCheckerController.php
+++ b/core/modules/auto_updates/src/Controller/ReadinessCheckerController.php
@@ -3,6 +3,7 @@
 namespace Drupal\auto_updates\Controller;
 
 use Drupal\auto_updates\ReadinessChecker\ReadinessCheckerManagerInterface;
+use Drupal\Core\Access\AccessResult;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\StringTranslation\TranslationInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -40,7 +41,7 @@ public function __construct(ReadinessCheckerManagerInterface $checker_manager, T
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('auto_updates.readiness_checker'),
+      $container->get('auto_updates.readiness_checker_manager'),
       $container->get('string_translation')
     );
   }
@@ -58,4 +59,14 @@ public function run() {
     return $this->redirect('auto_updates.settings');
   }
 
+  /**
+   * Checks access based on whether the readiness checkers are enabled.
+   *
+   * @return \Drupal\Core\Access\AccessResultInterface
+   *   The access result.
+   */
+  public function access() {
+    return AccessResult::allowedIf($this->checkerManager->isEnabled());
+  }
+
 }
diff --git a/core/modules/auto_updates/src/Form/SettingsForm.php b/core/modules/auto_updates/src/Form/SettingsForm.php
index a88eaaf14f..27ba01d1ae 100644
--- a/core/modules/auto_updates/src/Form/SettingsForm.php
+++ b/core/modules/auto_updates/src/Form/SettingsForm.php
@@ -31,7 +31,7 @@ class SettingsForm extends ConfigFormBase {
    */
   public static function create(ContainerInterface $container) {
     $instance = parent::create($container);
-    $instance->checkerManager = $container->get('auto_updates.readiness_checker');
+    $instance->checkerManager = $container->get('auto_updates.readiness_checker_manager');
     $instance->dateFormatter = $container->get('date.formatter');
     return $instance;
   }
diff --git a/core/modules/auto_updates/src/ReadinessChecker/ReadinessCheckerInterface.php b/core/modules/auto_updates/src/ReadinessChecker/ReadinessCheckerInterface.php
index b559d8fdd7..ca3031e6d4 100644
--- a/core/modules/auto_updates/src/ReadinessChecker/ReadinessCheckerInterface.php
+++ b/core/modules/auto_updates/src/ReadinessChecker/ReadinessCheckerInterface.php
@@ -3,7 +3,7 @@
 namespace Drupal\auto_updates\ReadinessChecker;
 
 /**
- * Interface for objects capable of readiness checking.
+ * Defines an interface for readiness checker services.
  */
 interface ReadinessCheckerInterface {
 
diff --git a/core/modules/auto_updates/tests/src/Functional/ReadinessCheckerTest.php b/core/modules/auto_updates/tests/src/Functional/ReadinessCheckerTest.php
index 99d81d968e..e42f21c6b3 100644
--- a/core/modules/auto_updates/tests/src/Functional/ReadinessCheckerTest.php
+++ b/core/modules/auto_updates/tests/src/Functional/ReadinessCheckerTest.php
@@ -51,12 +51,13 @@ protected function setUp(): void {
    */
   public function testReadinessChecksStatusReport() {
     $assert = $this->assertSession();
+    $page = $this->getSession()->getPage();
 
     $this->container->get('module_installer')->uninstall(['automated_cron']);
     $this->container->get('module_installer')->install(['auto_updates', 'auto_updates_test']);
 
     // If the the site is ready for updates the users will see the same output
-    // regardless of the user has permission to run updates.
+    // regardless of whether the user has permission to run updates.
     foreach ([$this->reportViewerUser, $this->checkerRunnerUser] as $user) {
       $this->drupalLogin($user);
       $this->drupalGet('admin/reports/status');
@@ -64,14 +65,14 @@ public function testReadinessChecksStatusReport() {
     }
 
     // Confirm a user without the permission to run readiness checks does not
-    // have a link to run the checks when the checks need to run again.
+    // have a link to run the checks when the checks need to be run again.
     $this->setFakeTime('+2 days');
     $this->drupalLogin($this->reportViewerUser);
     $this->drupalGet('admin/reports/status');
     $this->assertReadinessReportMatches('Your site has not recently checked if it is ready to apply automatic updates. Readiness checks were last run %s ago.');
 
     // Confirm a user with the permission to run readiness checks does have a
-    // link to run the checks when the checks need to run again.
+    // link to run the checks when the checks need to be run again.
     $this->drupalLogin($this->checkerRunnerUser);
     $this->drupalGet('admin/reports/status');
     $this->assertReadinessReportMatches('Your site has not recently checked if it is ready to apply automatic updates.'
@@ -83,6 +84,7 @@ public function testReadinessChecksStatusReport() {
     // @todo If coming from the status report page should you be redirected there?
     //   This is how 'Run cron" works.
     $assert->addressEquals('/admin/config/auto_updates');
+    $assert->checkboxChecked('enable_readiness_checks');
     $assert->pageTextNotContains("Access denied");
     $assert->pageTextContains('Your site is currently failing readiness checks for automatic updates. It cannot be automatically updated until further action is performed:');
     $assert->pageTextContains('OMG 🚒. Your server is on 🔥!');
@@ -92,9 +94,39 @@ public function testReadinessChecksStatusReport() {
       // Confirm the error is displayed on the status report page.
       $this->drupalGet('admin/reports/status');
       $this->assertReadinessReportMatches('1 check failed: OMG 🚒. Your server is on 🔥!');
-      // @todo Should always show when the checks were last run and a link to
+      // @todo Should we always show when the checks were last run and a link to
       //   run when there is an error?
     }
+
+    // Disable readiness checks.
+    $this->drupalLogin($this->checkerRunnerUser);
+    $this->drupalGet('admin/config/auto_updates');
+    $page->uncheckField('enable_readiness_checks');
+    $page->pressButton('Save configuration');
+
+    // Confirm that when readiness checkers are disabled no information on the
+    // last run is displayed.
+    $assert->pageTextNotContains('Readiness checks have never been run.');
+    $assert->pageTextNotContains('Readiness checks were last run');
+    $assert->pageTextNotContains('>run the readiness checks');
+
+    // Confirm that access is denied when manually going to the readiness
+    // checker controller.
+    $this->drupalGet('admin/config/auto_updates/readiness');
+    $assert->pageTextContains('Access denied');
+
+    $this->drupalGet('admin/reports/status');
+    $assert->pageTextNotContains('Update readiness checks');
+
+    // Re-enable readiness checks.
+    $this->drupalGet('admin/config/auto_updates');
+    $page->checkField('enable_readiness_checks');
+    $page->pressButton('Save configuration');
+
+    // Confirm that the last message displayed is displayed again.
+    $this->drupalGet('admin/reports/status');
+    $this->assertReadinessReportMatches('1 check failed: OMG 🚒. Your server is on 🔥!');
+
   }
 
   /**
@@ -121,6 +153,8 @@ public function testReadinessCheckAfterInstall() {
     $this->container->get('state')->set(TestChecker::STATE_KEY, 'Security has been compromised. "pass123" was a bad password!');
     $this->container->get('module_installer')->install(['color']);
     $this->drupalGet('admin/reports/status');
+    // Confirm that new checker message is not displayed because the checker was
+    // not run again.
     $this->assertReadinessReportMatches('1 check failed: 😿Oh no! A hacker now owns your files!');
 
     // Confirm the new message is displayed after running the checkers manually.
@@ -138,6 +172,8 @@ public function testReadinessCheckAfterInstall() {
    */
   public function testCronRun() {
     $assert = $this->assertSession();
+    $page = $this->getSession()->getPage();
+
     $this->drupalLogin($this->reportViewerUser);
     $this->container->get('module_installer')->install(['auto_updates', 'auto_updates_test']);
     $this->drupalGet('admin/reports/status');
@@ -163,10 +199,40 @@ public function testCronRun() {
     $this->setFakeTime('+125 minutes');
     $this->clickLink('Run cron');
     $this->assertReadinessReportMatches('1 check failed: OMG 💦. Now your server is filled with water!');
+
+    // Disable readiness checks.
+    $this->drupalLogin($this->checkerRunnerUser);
+    $this->drupalGet('admin/config/auto_updates');
+    $page->uncheckField('enable_readiness_checks');
+    $page->pressButton('Save configuration');
+
+    // Run cron while readiness checks are disabled.
+    $this->container->get('state')->set(TestChecker::STATE_KEY, '😨 Now your hard drive is missing! How is that even possible?');
+    $this->setFakeTime('+190 minutes');
+    $this->drupalGet('admin/reports/status');
+    $assert->pageTextNotContains('Update readiness checks');
+    $this->clickLink('Run cron');
+    $assert->pageTextNotContains('Update readiness checks');
+
+    // Re-enable readiness checks.
+    $this->drupalGet('admin/config/auto_updates');
+    $page->checkField('enable_readiness_checks');
+    $page->pressButton('Save configuration');
+
+    // Confirm that the new test message for the test readiness checker is not
+    // displayed because the checkers were not run during cron when they were
+    // disabled.
+    $this->drupalGet('admin/reports/status');
+    $this->assertReadinessReportMatches('1 check failed: OMG 💦. Now your server is filled with water!');
+
+    // Confirm running cron displays the new message.
+    $this->setFakeTime('+255 minutes');
+    $this->clickLink('Run cron');
+    $this->assertReadinessReportMatches('1 check failed: 😨 Now your hard drive is missing! How is that even possible?');
   }
 
   /**
-   * Sets a fake time that will be used in that test.
+   * Sets a fake time that will be used in the test.
    *
    * @param string $offset
    *   A date/time offset string.
diff --git a/core/modules/auto_updates/tests/src/Kernel/ReadinessChecker/DiskSpaceTest.php b/core/modules/auto_updates/tests/src/Kernel/ReadinessChecker/DiskSpaceTest.php
index 633b774a30..51a09e5aad 100644
--- a/core/modules/auto_updates/tests/src/Kernel/ReadinessChecker/DiskSpaceTest.php
+++ b/core/modules/auto_updates/tests/src/Kernel/ReadinessChecker/DiskSpaceTest.php
@@ -32,11 +32,16 @@ public function testDiskSpace() {
     $disk_space = new TestDiskSpace($this->container->getParameter('app.root'));
     $messages = $disk_space->run();
     $this->assertCount(2, $messages);
+    $this->assertStringMatchesFormat('Logical disk "%s" has insufficient space. There must be at least %s megabytes free.', (string) $messages[0]);
+    $this->assertStringMatchesFormat('Directory "%s" has insufficient space. There must be at least %s megabytes free.', (string) $messages[1]);
 
     // Out of space not the same logical disk.
     $disk_space = new TestDiskSpaceNonSameDisk($this->container->getParameter('app.root'));
     $messages = $disk_space->run();
     $this->assertCount(3, $messages);
+    $this->assertStringMatchesFormat('Drupal root filesystem "%s" has insufficient space. There must be at least %s megabytes free.', (string) $messages[0]);
+    $this->assertStringMatchesFormat('Vendor filesystem "%s" has insufficient space. There must be at least %s megabytes free.', (string) $messages[1]);
+    $this->assertStringMatchesFormat('Directory "%s" has insufficient space. There must be at least %s megabytes free.', (string) $messages[2]);
   }
 
 }