Index: firmware/App/Modes/ModePreGenDialysate.c
===================================================================
diff -u -r67731d57db9a620418b3b848d8f75ff204902c36 -r6d4aa77e6b85aa7621a234660f631e725fb1d441
--- firmware/App/Modes/ModePreGenDialysate.c	(.../ModePreGenDialysate.c)	(revision 67731d57db9a620418b3b848d8f75ff204902c36)
+++ firmware/App/Modes/ModePreGenDialysate.c	(.../ModePreGenDialysate.c)	(revision 6d4aa77e6b85aa7621a234660f631e725fb1d441)
@@ -1,22 +1,24 @@
 /**************************************************************************
 *
-* Copyright (c) 2025-2025 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2025-2026 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
 * @file    ModePreGenDialysate.c
 *
-* @author  (last)      Vinayakam Mani
-* @date    (last)      17-Apr-2025
+* @author  (last)      Raghu Kallala
+* @date    (last)      22-Apr-2026
 *
 * @author  (original)  Vinayakam Mani
-* @date    (original)  17-Apr-2025
+* @date    (original)  18-Apr-2025
 *
 ***************************************************************************/
 
+#include "BalancingChamber.h"
 #include "ConcentratePumps.h"
 #include "DialysatePumps.h"
+#include "DryBiCart.h"
 #include "Heaters.h"
 #include "ModePreGenDialysate.h"
 #include "ModeGenDialysate.h"
@@ -57,14 +59,14 @@
 static void publishPreGenDialysateState( void );
 static DD_PRE_GEN_DIALYSATE_STATE_T handlePreGenDialysateFillCompleteCheckState( void );
 static DD_PRE_GEN_DIALYSATE_STATE_T handlePreGenWetSelfTestState( void );
+static DD_PRE_GEN_DIALYSATE_STATE_T handleDryBicartInitialFillState( void );
 
 //Wet Self test
 static void setModePreGenWetSelfStateTransition( DD_WET_SELF_TEST_STATE_T state );
 static void execWetSelfTest( void );
 static DD_WET_SELF_TEST_STATE_T handleNegativeDeaerationPressureCheckState( void );
 static DD_WET_SELF_TEST_STATE_T handlePositiveDeaerationPressureCheckState( void );
 
-
 /*********************************************************************//**
  * @brief
  * The initPreGenDialysateMode function initializes the Pre-Generation
@@ -99,6 +101,8 @@
 {
     initPreGenDialysateMode();
     deenergizeActuators( PARK_CONC_PUMPS );
+    // Deactivate Balancing Chamber Switching
+    requestBalChamberSwitching( FALSE );
 
     setCurrentSubState( NO_SUB_STATE );
 
@@ -145,6 +149,10 @@
                 preGenDialysateState = handlePreGenWetSelfTestState();
                 break;
 
+            case DD_PRE_GEN_DRY_BICART_INITIAL_FILL:
+                preGenDialysateState = handleDryBicartInitialFillState();
+                break;
+
             case DD_PRE_GEN_DIALYSATE_WAIT_FOR_GEND:
                 // TODO : handle wait for Gen dialysate
                 break;
@@ -242,15 +250,52 @@
 static DD_PRE_GEN_DIALYSATE_STATE_T handlePreGenWetSelfTestState( void )
 {
     //TODO: Change to wet self test state later
-    DD_PRE_GEN_DIALYSATE_STATE_T state  = DD_PRE_GEN_DIALYSATE_WAIT_FOR_GEND;
+    DD_PRE_GEN_DIALYSATE_STATE_T state  = DD_PRE_GEN_DRY_BICART_INITIAL_FILL;
 
+    // TODO: testing drybicart fill in pre-gen
+    if ( getTestConfigStatus( TEST_CONFIG_DD_DRY_BICART_TEST ) == TRUE )
+    {
+        setBicartFillRequested();
+    }
+
     //execWetSelfTest();
 
     return state;
 }
 
 /*********************************************************************//**
  * @brief
+ * The handleDryBicartInitialFillState function executes intial dry bicart fill request
+ * @details \b Inputs: none
+ * @details \b Outputs: none
+ * @return current state of PreGenDialysate mode
+ *************************************************************************/
+static DD_PRE_GEN_DIALYSATE_STATE_T handleDryBicartInitialFillState( void )
+{
+    //TODO: Change to wet self test state later
+    DD_PRE_GEN_DIALYSATE_STATE_T state  = DD_PRE_GEN_DRY_BICART_INITIAL_FILL;
+
+    // TODO: testing drybicart fill in pre-gen
+    if ( getTestConfigStatus( TEST_CONFIG_DD_DRY_BICART_TEST ) == TRUE )
+    {
+        // stay in this state till bicart fill complete.
+        if ( getCurrentDryBiCartFillExecState() == DRY_BICART_FILL_COMPLETE_STATE )
+        {
+             state   = DD_PRE_GEN_DIALYSATE_WAIT_FOR_GEND;
+        }
+        // TODO: Alarm if it is not completed within 1.5 minutes
+    }
+    else
+    {
+        // not bicart fill, move to next state
+        state   = DD_PRE_GEN_DIALYSATE_WAIT_FOR_GEND;
+    }
+
+    return state;
+}
+
+/*********************************************************************//**
+ * @brief
  * The setModePreGenWetSelfStateTransition function sets the actuators and variables
  * for the state transition in pre-gen WetSlef test mode.
  * @details Inputs: Valve states, Pump speed
@@ -268,9 +313,6 @@
             break;
 
         case DD_WET_SELF_TEST_NEGATIVE_DEAERATION_PRES_CHECK:
-            //Make sure Water Inlet Valve is open
-            setValveState( DD_M4_VALV, VALVE_STATE_OPEN );
-
             // Start timer for hyd chamber negative pressure check state
             hydChamberPressureCheckStartTimeMS = getMSTimerCount();
             // Start D12/Degassing pump - closed loop control
@@ -471,4 +513,67 @@
     return result;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The testValidateDDPreGenDialysateChangeReq function validate whether request
+ * operation sub mode is legal or not.
+ * @details \b Inputs: none
+ * @details \b Outputs: none
+ * @param newSubMode the enumerated sub state of the mode
+ * @return TRUE if request is legal, FALSE if not
+ *************************************************************************/
+BOOL testValidateDDPreGenDialysateChangeReq( U32 newSubMode )
+{
+    BOOL result = FALSE;
+
+    if ( newSubMode < NUM_OF_DD_PRE_GEN_DIALYSATE_STATES )
+    {
+        switch ( newSubMode )
+        {
+            // TODO add validate condition after checking with Vinay
+            case DD_PRE_GEN_DIALYSATE_HYD_CHAMBER_FILL_CHECK:
+            case DD_PRE_GEN_WET_SELF_TEST:
+            case DD_PRE_GEN_DRY_BICART_INITIAL_FILL:
+            case DD_PRE_GEN_DIALYSATE_WAIT_FOR_GEND:
+                result = TRUE;
+                break;
+
+            default:
+                break;
+        }
+    }
+
+    return result;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The testSignalNewDDPreGenDialysateSubMode function request transition
+ * to a new operation sub mode.
+ * @details \b Inputs: none
+ * @details \b Outputs: preGenDialysateState
+ * @param newSubMode the enumerated sub state of the mode
+ * @return none
+ *************************************************************************/
+void testSignalNewDDPreGenDialysateSubMode( U32 newSubMode )
+{
+    if ( newSubMode < NUM_OF_DD_PRE_GEN_DIALYSATE_STATES )
+    {
+        preGenDialysateState = (DD_PRE_GEN_DIALYSATE_STATE_T)newSubMode;
+
+        switch ( newSubMode )
+        {
+            // TODO add logic after checking with Vinay
+            // Any of these state require no special handling
+            case DD_PRE_GEN_DIALYSATE_HYD_CHAMBER_FILL_CHECK:
+            case DD_PRE_GEN_WET_SELF_TEST:
+            case DD_PRE_GEN_DRY_BICART_INITIAL_FILL:
+            case DD_PRE_GEN_DIALYSATE_WAIT_FOR_GEND:
+            default:
+                break;
+        }
+        // TODO should setState handled separately for wet self state?
+    }
+}
+
 /**@}*/