Index: firmware/App/Modes/FPModes/FPOperationModes.c
===================================================================
diff -u -rc07917caced76b53a0ed8f35167fac6f9d8310a4 -rf4a8565c7edec12094b8a737ed7b8cd3424a9208
--- firmware/App/Modes/FPModes/FPOperationModes.c	(.../FPOperationModes.c)	(revision c07917caced76b53a0ed8f35167fac6f9d8310a4)
+++ firmware/App/Modes/FPModes/FPOperationModes.c	(.../FPOperationModes.c)	(revision f4a8565c7edec12094b8a737ed7b8cd3424a9208)
@@ -7,8 +7,8 @@
 *
 * @file    FPOperationModes.c
 *
-* @author  (last)      Michael Garthwaite
-* @date    (last)      30-Oct-2025
+* @author  (last)      “rkallala”
+* @date    (last)      09-Dec-2025
 *
 * @author  (original)  Michael Garthwaite
 * @date    (original)  08-Sep-2025
@@ -131,7 +131,7 @@
     // Is requested new mode valid and legal at this time?
     if ( ( newMode >= FP_MODE_NLEG ) && ( isTestingActivated() != TRUE ) )
     {
-        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, SW_FAULT_ID_OP_MODES_ILLEGAL_MODE_TRANSITION_REQUESTED, newMode )
+        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, FP_FAULT_ID_OP_MODES_ILLEGAL_MODE_TRANSITION_REQUESTED, newMode )
         newMode = currentMode;
     }
 
@@ -181,7 +181,7 @@
             break;
 
         default:
-            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, SW_FAULT_ID_OP_MODES_INVALID_MODE_STATE, currentMode )
+            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, FP_FAULT_ID_OP_MODES_INVALID_MODE_STATE, currentMode )
             currentMode = FP_MODE_FAUL;
             currentSubMode = 0;
             break;
@@ -220,7 +220,7 @@
     }
     else
     {  // Invalid mode requested
-        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, SW_FAULT_ID_OP_MODES_INVALID_MODE_REQUESTED, newMode )
+        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, FP_FAULT_ID_OP_MODES_INVALID_MODE_REQUESTED, newMode )
     }
 }
 
@@ -348,7 +348,7 @@
 
 
         default:
-            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, SW_FAULT_ID_OP_MODES_INVALID_MODE_TO_TRANSITION_TO, newMode )
+            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_FP_SOFTWARE_FAULT, FP_FAULT_ID_OP_MODES_ILLEGAL_MODE_TRANSITION_REQUESTED, newMode )
             break;
     }
 }
@@ -405,7 +405,7 @@
  * The isFPDefeatured function returns if the Leahi device is defeatured.
  * @details \b Inputs: none
  * @details \b Outputs: none
- * @return the boolean if the FP device is defeatured.
+ * @return TRUE if FP device is de-featured, FALSE if not.
  *************************************************************************/
 BOOL isFPDefeatured( void )
 {
@@ -419,7 +419,7 @@
  * has a boost pump installed.
  * @details \b Inputs: none
  * @details \b Outputs: none
- * @return the boolean if boost pump is installed.
+ * @return TRUE if FP device is contains a boost pump, FALSE if not.
  *************************************************************************/
 BOOL isBoostPumpInstalled( void )
 {
@@ -433,21 +433,29 @@
  * has a boost pump installed.
  * @details \b Inputs: none
  * @details \b Outputs: none
- * @return the rejection reason codes for stopping generate permeate.
+ * @return the rejection reason code for stopping generate permeate.
  *************************************************************************/
 REQUEST_REJECT_REASON_CODE_T signalStopGenPermeate( void )
 {
     REQUEST_REJECT_REASON_CODE_T reason = REQUEST_REJECT_REASON_NONE;
+    BOOL result = FALSE;
+
     // Stop is agnostic to defeatured/featured.
     // As long as were not in fault or POST, request to go to standby to stop
-    if ( currentMode >= FP_MODE_STAN )
+    if ( TRUE == isFPDefeatured() )
     {
-        requestNewFPOperationMode( FP_MODE_STAN );
+        result = requestPreGenDefStop();
     }
     else
     {
+        result = requestPreGenStop();
+    }
+
+    if ( FALSE == result )
+    {
         reason = REQUEST_REJECT_REASON_NOT_ALLOWED_IN_CURRENT_MODE;
     }
+
     return reason;
 }
 
@@ -457,20 +465,28 @@
  * has a boost pump installed.
  * @details \b Inputs: none
  * @details \b Outputs: none
- * @return the rejection reason codes for starting generate permeate.
+ * @return the rejection reason code for starting generate permeate.
  *************************************************************************/
 REQUEST_REJECT_REASON_CODE_T signalStartGenPermeate( void )
 {
     REQUEST_REJECT_REASON_CODE_T reason = REQUEST_REJECT_REASON_NONE;
+    BOOL result = FALSE;
+
     // TODO - Service and disinfection checks happen here.
     if ( TRUE == isFPDefeatured() )
     {
-        requestNewFPOperationMode( FP_MODE_DPGP );
+        result = requestPreGenDefStart();
     }
     else
     {
-        requestNewFPOperationMode( FP_MODE_PGEN );
+        result = requestPreGenStart();
     }
+
+    if ( FALSE == result )
+    {
+        reason = REQUEST_REJECT_REASON_NOT_ALLOWED_IN_CURRENT_MODE;
+    }
+
     return reason;
 }