Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -rc62f5bfffa8e54b86c8e320bee344308b368f96d -rd8b6a463f9e65c8ac145cf634d5d6641fb3bbd89
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision c62f5bfffa8e54b86c8e320bee344308b368f96d)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision d8b6a463f9e65c8ac145cf634d5d6641fb3bbd89)
@@ -376,6 +376,12 @@
 {
     HD_PRE_TREATMENT_MODE_STATE_T state = HD_PRE_TREATMENT_SELF_TEST_DRY_STATE;
 
+    if ( FALSE == getDoorState() )
+    {
+        activateAlarmNoData( ALARM_ID_CARTRIDGE_DOOR_OPENED );
+        state = HD_PRE_TREATMENT_CART_INSTALL_STATE;
+    }
+
     if ( FALSE == isBloodPumpRunning() )
     {
         transitionToPrime();