Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -rfee71ca73745dad573b28acd13b66624cceeabc0 -r6e07046677cba738be6f78b155f4f23120a43081
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision fee71ca73745dad573b28acd13b66624cceeabc0)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision 6e07046677cba738be6f78b155f4f23120a43081)
@@ -59,8 +59,10 @@
 {
     PRIME_RESERVOIR_MGMT_START_STATE = 0,                    ///< If DG not already in re-circ mode, try to get it there.
     PRIME_RESERVOIR_MGMT_FLUSH_DG_LINES_STATE,               ///< In DG re-circ, wait for lines to flush - then start draining inactive reservoir.
+    PRIME_RESERVOIR_MGMT_WAIT_FOR_DRAIN_CMD_RESP,            ///< After sending drain command, wait for DG to response back.
     PRIME_RESERVOIR_MGMT_DRAIN_STATE,                        ///< Wait for drain to complete.
     PRIME_RESERVOIR_MGMT_START_FILL_STATE,                   ///< Command DG to start filling reservoir.
+    PRIME_RESERVOIR_MGMT_WAIT_FOR_FILL_CMD_RESP,             ///< After sending fill command, wait for DG to response back.
     PRIME_RESERVOIR_MGMT_FILL_STATE,                         ///< Wait for fill to complete.
     PRIME_RESERVOIR_MGMT_FILL_COMPLETE_STATE,                ///< Reservoir fill has completed.
     PRIME_RESERVOIR_MGMT_WAIT_RESERVOIR_TWO_INACTIVE,        ///< Wait for reservoir 2 become inactive.
@@ -89,7 +91,7 @@
 // ********** private function prototypes **********
 
 static void broadcastPrimingStatus( void );
-static void execPreTreatmentReservoirMgmt( void );
+static void execPrimeReservoirMgmt( void );
 static void purgeAirValvesBloodPumpControl( void );
 
 static HD_PRE_TREATMENT_PRIME_STATE_T handlePrimeSalineSetupState( void );
@@ -196,7 +198,7 @@
     broadcastPrimingStatus();
 
     // Exec reservoir management for priming
-    execPreTreatmentReservoirMgmt();
+    execPrimeReservoirMgmt();
 }
 
 /*********************************************************************//**
@@ -243,41 +245,55 @@
 
 /*********************************************************************//**
  * @brief
- * The execPreTreatmentReservoirMgmt function executes the state machine for the
- * reservoir management during pre-treatment mode.
+ * The execPrimeReservoirMgmt function executes the state machine for the
+ * reservoir management during pre-treatment prime sub-mode.
  * @details Inputs: currentReservoirMgmtState
  * @details Outputs: DG reservoirs' fills managed.
  * @return none
  *************************************************************************/
-static void execPreTreatmentReservoirMgmt( void )
+static void execPrimeReservoirMgmt( void )
 {
+    DG_CMD_RESPONSE_T dgCmdResp;
+
+    getDGCommandResponse( &dgCmdResp );
     DG_OP_MODE_T dgOpMode = getDGOpMode();
     U32 dgSubMode = getDGSubMode();
 
+
     // treatment reservoir mgmt. state machine
     switch ( currentReservoirMgmtState )
     {
         case PRIME_RESERVOIR_MGMT_START_STATE:
+            currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_FLUSH_DG_LINES_STATE;
+            break;
+
+        case PRIME_RESERVOIR_MGMT_FLUSH_DG_LINES_STATE:
             if ( DG_MODE_CIRC == dgOpMode )
             {
-                currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_FLUSH_DG_LINES_STATE;
+                if ( DG_RECIRCULATE_MODE_STATE_RECIRC_WATER == dgSubMode )
+                {
+                    currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_WAIT_FOR_DRAIN_CMD_RESP;
+                    cmdStartDGDrain( PRIME_DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+                }
             }
             else
             {
-                cmdStartDG();
+                // TODO Handle when DG mode is out of sync
             }
             break;
 
-        case PRIME_RESERVOIR_MGMT_FLUSH_DG_LINES_STATE:
-            if ( ( DG_MODE_CIRC == dgOpMode ) && ( DG_RECIRCULATE_MODE_STATE_RECIRC_WATER == dgSubMode ) )
+        case PRIME_RESERVOIR_MGMT_WAIT_FOR_DRAIN_CMD_RESP:
+            if ( DG_CMD_START_DRAIN == dgCmdResp.commandID )
             {
-                cmdStartDGDrain( PRIME_DRAIN_RESERVOIR_TO_VOLUME_ML, TRUE );
+                if ( FALSE == dgCmdResp.rejected )
+                {
+                    currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_DRAIN_STATE;
+                }
+                else if ( DG_CMD_REQUEST_REJECT_REASON_INVALID_MODE == dgCmdResp.rejected )
+                {
+                    currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_FLUSH_DG_LINES_STATE;
+                }
             }
-
-            if ( DG_MODE_DRAI == dgOpMode )
-            {
-                currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_DRAIN_STATE;
-            }
             break;
 
         case PRIME_RESERVOIR_MGMT_DRAIN_STATE:
@@ -290,11 +306,22 @@
         case PRIME_RESERVOIR_MGMT_START_FILL_STATE:
             if ( ( DG_MODE_CIRC == dgOpMode ) && ( DG_RECIRCULATE_MODE_STATE_RECIRC_WATER == dgSubMode ) )
             {
+                currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_WAIT_FOR_FILL_CMD_RESP;
                 cmdStartDGFill( PRIME_FILL_RESERVOIR_TO_VOLUME_ML );
             }
-            if ( DG_MODE_FILL == dgOpMode )
+            break;
+
+        case PRIME_RESERVOIR_MGMT_WAIT_FOR_FILL_CMD_RESP:
+            if ( DG_CMD_START_FILL == dgCmdResp.commandID )
             {
-                currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_FILL_STATE;
+                if ( FALSE == dgCmdResp.rejected )
+                {
+                    currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_FILL_STATE;
+                }
+                else if ( DG_CMD_REQUEST_REJECT_REASON_INVALID_MODE == dgCmdResp.rejected )
+                {
+                    currentReservoirMgmtState = PRIME_RESERVOIR_MGMT_START_FILL_STATE;
+                }
             }
             break;