Index: firmware/App/Modes/SelfTests.c
===================================================================
diff -u -rd8b6a463f9e65c8ac145cf634d5d6641fb3bbd89 -r180f01b2abd71939b5265069e88d85dea4eec393
--- firmware/App/Modes/SelfTests.c	(.../SelfTests.c)	(revision d8b6a463f9e65c8ac145cf634d5d6641fb3bbd89)
+++ firmware/App/Modes/SelfTests.c	(.../SelfTests.c)	(revision 180f01b2abd71939b5265069e88d85dea4eec393)
@@ -58,6 +58,7 @@
 {
     DRY_SELF_TESTS_START_STATE = 0,                         ///< Dry self-tests starting state.
     DRY_SELF_TESTS_BUBBLE_DETECTOR_STATE,                   ///< Bubble detectors dry self-tests state.
+    DRY_SELF_TESTS_AIR_TRAP_STATE,                          ///< Air trap fill level ultrasonic sensor dry self-tests state.
     DRY_SELF_TESTS_OCCLUSION_SENSORS_STATE,                 ///< Occlusion sensors dry self-tests state.
     DRY_SELF_TESTS_COMPLETE,                                ///< Dry self-test complete state.
     NUM_OF_DRY_SELF_TESTS_STATES                            ///< Number of no cartridge self-tests states.
@@ -258,7 +259,7 @@
 
                 if ( ( TRUE == isADADetectedAir ) && ( TRUE == isADADetectedAir ) )
                 {
-                    currentDrySelfTestsState = DRY_SELF_TESTS_OCCLUSION_SENSORS_STATE;
+                    currentDrySelfTestsState = DRY_SELF_TESTS_AIR_TRAP_STATE;
                 }
                 else
                 {
@@ -267,6 +268,18 @@
             }
             break;
 
+        case DRY_SELF_TESTS_AIR_TRAP_STATE:
+            if ( ( AIR_TRAP_LEVEL_AIR == getAirTrapLevel( AIR_TRAP_LEVEL_SENSOR_LOWER ) ) &&
+                 ( AIR_TRAP_LEVEL_AIR == getAirTrapLevel( AIR_TRAP_LEVEL_SENSOR_UPPER ) ) )
+            {
+                currentDrySelfTestsState = DRY_SELF_TESTS_OCCLUSION_SENSORS_STATE;
+            }
+            else
+            {
+                activateAlarmNoData( ALARM_ID_INSTALL_NEW_CARTRIDGE );
+            }
+            break;
+
         case DRY_SELF_TESTS_OCCLUSION_SENSORS_STATE:
             currentDrySelfTestsState = DRY_SELF_TESTS_COMPLETE;
             break;