diff --git a/awx/main/scheduler/__init__.py b/awx/main/scheduler/__init__.py
index a6f477539c..670012dc57 100644
--- a/awx/main/scheduler/__init__.py
+++ b/awx/main/scheduler/__init__.py
@@ -421,26 +421,40 @@ class TaskManager():
             if not found_acceptable_queue:
                 logger.debug("%s couldn't be scheduled on graph, waiting for next cycle", task.log_format)
 
-    def fail_jobs_if_not_in_celery(self, node_jobs, active_tasks, celery_task_start_time):
+    def fail_jobs_if_not_in_celery(self, node_jobs, active_tasks, celery_task_start_time,
+                                   isolated=False):
         for task in node_jobs:
             if (task.celery_task_id not in active_tasks and not hasattr(settings, 'IGNORE_CELERY_INSPECTOR')):
                 if isinstance(task, WorkflowJob):
                     continue
                 if task.modified > celery_task_start_time:
                     continue
-                task.status = 'failed'
-                task.job_explanation += ' '.join((
-                    'Task was marked as running in Tower but was not present in',
-                    'Celery, so it has been marked as failed.',
-                ))
+                new_status = 'failed'
+                if isolated:
+                    new_status = 'error'
+                task.status = new_status
+                if isolated:
+                    # TODO: cancel and reap artifacts of lost jobs from heartbeat
+                    task.job_explanation += ' '.join((
+                        'Task was marked as running in Tower but its ',
+                        'controller management daemon was not present in',
+                        'Celery, so it has been marked as failed.',
+                        'Task may still be running, but contactability is unknown.'
+                    ))
+                else:
+                    task.job_explanation += ' '.join((
+                        'Task was marked as running in Tower but was not present in',
+                        'Celery, so it has been marked as failed.',
+                    ))
                 try:
                     task.save(update_fields=['status', 'job_explanation'])
                 except DatabaseError:
                     logger.error("Task {} DB error in marking failed. Job possibly deleted.".format(task.log_format))
                     continue
                 awx_tasks._send_notification_templates(task, 'failed')
-                task.websocket_emit_status('failed')
-                logger.error("Task {} has no record in celery. Marking as failed".format(task.log_format))
+                task.websocket_emit_status(new_status)
+                logger.error("{}Task {} has no record in celery. Marking as failed".format(
+                    'Isolated ' if isolated else '', task.log_format))
 
     def cleanup_inconsistent_celery_tasks(self):
         '''
@@ -471,26 +485,36 @@ class TaskManager():
         self.fail_jobs_if_not_in_celery(waiting_tasks, all_celery_task_ids, celery_task_start_time)
 
         for node, node_jobs in running_tasks.iteritems():
+            isolated = False
             if node in active_queues:
                 active_tasks = active_queues[node]
             else:
                 '''
-                Node task list not found in celery. If tower thinks the node is down
-                then fail all the jobs on the node.
+                Node task list not found in celery. We may branch into cases:
+                 - instance is unknown to tower, system is improperly configured
+                 - instance is reported as down, then fail all jobs on the node
+                 - instance is an isolated node, then check running tasks
+                    among all allowed controller nodes for management process
                 '''
-                try:
-                    instance = Instance.objects.get(hostname=node)
-                    if instance.capacity == 0:
-                        active_tasks = []
-                    else:
-                        continue
-                except Instance.DoesNotExist:
-                    logger.error("Execution node Instance {} not found in database. "
-                                 "The node is currently executing jobs {}".format(node, 
-                                                                                  [j.log_format for j in node_jobs]))
-                    active_tasks = []
+                instance = Instance.objects.filter(hostname=node).first()
 
-            self.fail_jobs_if_not_in_celery(node_jobs, active_tasks, celery_task_start_time)
+                if instance is None:
+                    logger.error("Execution node Instance {} not found in database. "
+                                 "The node is currently executing jobs {}".format(
+                                     node, [j.log_format for j in node_jobs]))
+                    active_tasks = []
+                elif instance.capacity == 0:
+                    active_tasks = []
+                elif instance.rampart_groups.filter(controller__isnull=False).exists():
+                    active_tasks = all_celery_task_ids
+                    isolated = True
+                else:
+                    continue
+
+            self.fail_jobs_if_not_in_celery(
+                node_jobs, active_tasks, celery_task_start_time,
+                isolated=isolated
+            )
 
     def calculate_capacity_consumed(self, tasks):
         self.graph = InstanceGroup.objects.capacity_values(tasks=tasks, graph=self.graph)
diff --git a/awx/main/tests/unit/test_task_manager.py b/awx/main/tests/unit/test_task_manager.py
index 65b7607bb4..1937b7b5ca 100644
--- a/awx/main/tests/unit/test_task_manager.py
+++ b/awx/main/tests/unit/test_task_manager.py
@@ -21,7 +21,7 @@ class TestCleanupInconsistentCeleryTasks():
     @mock.patch.object(TaskManager, 'get_active_tasks', return_value=([], {}))
     @mock.patch.object(TaskManager, 'get_running_tasks', return_value=({'host1': [Job(id=2), Job(id=3),]}, []))
     @mock.patch.object(InstanceGroup.objects, 'prefetch_related', return_value=[])
-    @mock.patch.object(Instance.objects, 'get', side_effect=Instance.DoesNotExist)
+    @mock.patch.object(Instance.objects, 'filter', return_value=mock.MagicMock(first=lambda: None))
     @mock.patch('awx.main.scheduler.logger')
     def test_instance_does_not_exist(self, logger_mock, *args):
         logger_mock.error = mock.MagicMock(side_effect=RuntimeError("mocked"))