Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r3d72b777cf1ceb673d118341c46e2d6d5b7b75f5 -r3d3cc1e6819f83db631270dc0fd019d15739db08
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 3d72b777cf1ceb673d118341c46e2d6d5b7b75f5)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 3d3cc1e6819f83db631270dc0fd019d15739db08)
@@ -263,16 +263,50 @@
  *************************************************************************/
 void signalUserConfirmInstallation( void )
 {
+    BOOL accepted = FALSE;
+    REQUEST_REJECT_REASON_CODE_T rejReason = REQUEST_REJECT_REASON_NONE;
+
+    confirmInstallRequested = FALSE;
+
     F32 bolusVol = getTreatmentParameterF32( TREATMENT_PARAM_HEPARIN_BOLUS_VOLUME );
     F32 hepRate  = getTreatmentParameterF32( TREATMENT_PARAM_HEPARIN_DISPENSE_RATE );
 
-    // Accept installation confirmation if we are in install state of pre-treatment mode and syringe is detected or Heparin not being used in this treatment.
+    // Accept installation confirmation if we are in install state of pre-treatment mode and
+    // Door closed, Cartridge installed, syringe is detected or Heparin not being used in this treatment.
     if ( ( MODE_PRET == getCurrentOperationMode() ) &&
-         ( HD_PRE_TREATMENT_CART_INSTALL_STATE == currentPreTreatmentState ) &&
-         ( ( TRUE == isSyringeDetected() ) || ( ( bolusVol < NEARLY_ZERO ) && ( hepRate < NEARLY_ZERO ) ) ) )
+         ( HD_PRE_TREATMENT_CART_INSTALL_STATE == currentPreTreatmentState ) )
     {
-        confirmInstallRequested = TRUE;
+        if ( STATE_CLOSED == getSwitchStatus( FRONT_DOOR ) )
+        {
+            if ( CONSUMABLE_SELF_TESTS_COMPLETE_STATE == getConsumableSelfTestState() )
+            {
+                if ( ( TRUE == isSyringeDetected() ) || ( ( bolusVol < NEARLY_ZERO ) && ( hepRate < NEARLY_ZERO ) ) )
+                {
+                    // Everything is properly installed
+                    accepted = TRUE;
+                    confirmInstallRequested = TRUE;
+                }
+                else
+                {
+                    rejReason = REQUEST_REJECT_REASON_SYRINGE_NOT_PRESENT;
+                }
+            }
+            else
+            {
+                rejReason = REQUEST_REJECT_REASON_CONSUMABLE_NOT_READY;
+            }
+        }
+        else
+        {
+            rejReason = REQUEST_REJECT_REASON_DOOR_NOT_CLOSED;
+        }
     }
+    else
+    {
+        rejReason = REQUEST_REJECT_REASON_ACTION_DISABLED_IN_CURRENT_STATE;
+    }
+
+    sendConsumableInstallCmdResponse( accepted, (U32) rejReason );
 }
 
 /*********************************************************************//**
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r3d72b777cf1ceb673d118341c46e2d6d5b7b75f5 -r3d3cc1e6819f83db631270dc0fd019d15739db08
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 3d72b777cf1ceb673d118341c46e2d6d5b7b75f5)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 3d3cc1e6819f83db631270dc0fd019d15739db08)
@@ -1201,6 +1201,21 @@
 
 /*********************************************************************//**
  * @brief
+ * The sendConsumableInstallCmdResponse function constructs a Consumable Install Confirm user action
+ * response to the UI and queues the msg for transmit on the appropriate CAN channel.
+ * @details Inputs: none
+ * @details Outputs: Consumable Install Confirm command response msg constructed and queued.
+ * @param accepted T/F - was Consumable Install Confirm request accepted?
+ * @param reason reason why request was rejected (or zero if accepted)
+ * @return TRUE if msg successfully queued for transmit, FALSE if not
+ *************************************************************************/
+BOOL sendConsumableInstallCmdResponse( BOOL accepted, U32 reason )
+{
+    return sendUIResponseMsg( MSG_ID_UI_INSTALLATION_CONFIRM_RESPONSE, accepted, reason );
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleInstallationConfirm function handles user confirms disposable
  * installation msg from the UI.
  * @details Inputs: none
Index: firmware/App/Services/SystemCommMessages.h
===================================================================
diff -u -r3d72b777cf1ceb673d118341c46e2d6d5b7b75f5 -r3d3cc1e6819f83db631270dc0fd019d15739db08
--- firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 3d72b777cf1ceb673d118341c46e2d6d5b7b75f5)
+++ firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 3d3cc1e6819f83db631270dc0fd019d15739db08)
@@ -254,6 +254,9 @@
 // MSG_ID_UI_CONSUMABLE_INSTALL_CONFIRM
 void handleConsumableInstallConfirm( MESSAGE_T *message );
 
+// MSG_ID_UI_INSTALLATION_CONFIRM_RESPONSE
+BOOL sendConsumableInstallCmdResponse( BOOL accepted, U32 reason );
+
 // MSG_ID_UI_INSTALLATION_CONFIRM
 void handleInstallationConfirm( MESSAGE_T *message );