diff --git a/controller_manager/CMakeLists.txt b/controller_manager/CMakeLists.txt
index 689e7c7244..b3f0f59a2c 100644
--- a/controller_manager/CMakeLists.txt
+++ b/controller_manager/CMakeLists.txt
@@ -9,6 +9,7 @@ set(THIS_PACKAGE_INCLUDE_DEPENDS
     ament_index_cpp
     controller_interface
     controller_manager_msgs
+    diagnostic_updater
     hardware_interface
     pluginlib
     rclcpp
diff --git a/controller_manager/include/controller_manager/controller_manager.hpp b/controller_manager/include/controller_manager/controller_manager.hpp
index 4b03a3b4f4..5985bb37af 100644
--- a/controller_manager/include/controller_manager/controller_manager.hpp
+++ b/controller_manager/include/controller_manager/controller_manager.hpp
@@ -40,6 +40,7 @@
 #include "controller_manager_msgs/srv/switch_controller.hpp"
 #include "controller_manager_msgs/srv/unload_controller.hpp"
 
+#include "diagnostic_updater/diagnostic_updater.hpp"
 #include "hardware_interface/handle.hpp"
 #include "hardware_interface/resource_manager.hpp"
 
@@ -394,6 +395,9 @@ class ControllerManager : public rclcpp::Node
    */
   rclcpp::NodeOptions determine_controller_node_options(const ControllerSpec & controller) const;
 
+  void controller_activity_diagnostic_callback(diagnostic_updater::DiagnosticStatusWrapper & stat);
+  diagnostic_updater::Updater diagnostics_updater_;
+
   std::shared_ptr<rclcpp::Executor> executor_;
 
   std::shared_ptr<pluginlib::ClassLoader<controller_interface::ControllerInterface>> loader_;
diff --git a/controller_manager/package.xml b/controller_manager/package.xml
index ee25fd1047..ddf68e5b6a 100644
--- a/controller_manager/package.xml
+++ b/controller_manager/package.xml
@@ -16,6 +16,7 @@
   <depend>backward_ros</depend>
   <depend>controller_interface</depend>
   <depend>controller_manager_msgs</depend>
+  <depend>diagnostic_updater</depend>
   <depend>hardware_interface</depend>
   <depend>launch</depend>
   <depend>launch_ros</depend>
diff --git a/controller_manager/src/controller_manager.cpp b/controller_manager/src/controller_manager.cpp
index 7d5672519a..d38bea3e70 100644
--- a/controller_manager/src/controller_manager.cpp
+++ b/controller_manager/src/controller_manager.cpp
@@ -277,7 +277,8 @@ ControllerManager::ControllerManager(
       kControllerInterfaceNamespace, kControllerInterfaceClassName)),
   chainable_loader_(
     std::make_shared<pluginlib::ClassLoader<controller_interface::ChainableControllerInterface>>(
-      kControllerInterfaceNamespace, kChainableControllerInterfaceClassName))
+      kControllerInterfaceNamespace, kChainableControllerInterfaceClassName)),
+  diagnostics_updater_(this)
 {
   if (!get_parameter("update_rate", update_rate_))
   {
@@ -299,6 +300,11 @@ ControllerManager::ControllerManager(
     init_resource_manager(robot_description);
     init_services();
   }
+
+  diagnostics_updater_.setHardwareID("ros2_control");
+  diagnostics_updater_.add(
+    "Controllers Activity", this, &ControllerManager::controller_activity_diagnostic_callback);
+  init_services();
 }
 
 ControllerManager::ControllerManager(
@@ -313,7 +319,8 @@ ControllerManager::ControllerManager(
       kControllerInterfaceNamespace, kControllerInterfaceClassName)),
   chainable_loader_(
     std::make_shared<pluginlib::ClassLoader<controller_interface::ChainableControllerInterface>>(
-      kControllerInterfaceNamespace, kChainableControllerInterfaceClassName))
+      kControllerInterfaceNamespace, kChainableControllerInterfaceClassName)),
+  diagnostics_updater_(this)
 {
   if (!get_parameter("update_rate", update_rate_))
   {
@@ -328,6 +335,11 @@ ControllerManager::ControllerManager(
   {
     init_services();
   }
+
+  diagnostics_updater_.setHardwareID("ros2_control");
+  diagnostics_updater_.add(
+    "Controllers Activity", this, &ControllerManager::controller_activity_diagnostic_callback);
+  init_services();
 }
 
 ControllerManager::~ControllerManager()
@@ -2546,6 +2558,32 @@ controller_interface::return_type ControllerManager::check_preceeding_controller
   return controller_interface::return_type::OK;
 }
 
+void ControllerManager::controller_activity_diagnostic_callback(
+  diagnostic_updater::DiagnosticStatusWrapper & stat)
+{
+  // lock controllers
+  std::lock_guard<std::recursive_mutex> guard(rt_controllers_wrapper_.controllers_lock_);
+  const std::vector<ControllerSpec> & controllers = rt_controllers_wrapper_.get_updated_list(guard);
+  bool all_active = true;
+  for (size_t i = 0; i < controllers.size(); ++i)
+  {
+    if (!is_controller_active(controllers[i].c))
+    {
+      all_active = false;
+    }
+    stat.add(controllers[i].info.name, controllers[i].c->get_state().label());
+  }
+
+  if (all_active)
+  {
+    stat.summary(diagnostic_msgs::msg::DiagnosticStatus::OK, "All controllers are active");
+  }
+  else
+  {
+    stat.summary(diagnostic_msgs::msg::DiagnosticStatus::ERROR, "Not all controllers are active");
+  }
+}
+
 bool ControllerManager::controller_sorting(
   const ControllerSpec & ctrl_a, const ControllerSpec & ctrl_b,
   const std::vector<controller_manager::ControllerSpec> & controllers)
@@ -2669,7 +2707,7 @@ bool ControllerManager::controller_sorting(
     // The rest of the cases, basically end up at the end of the list
     return false;
   }
-};
+}
 
 rclcpp::NodeOptions ControllerManager::determine_controller_node_options(
   const ControllerSpec & controller) const