Index: firmware/App/Controllers/BloodFlow.c
===================================================================
diff -u -r6f02ff4686ec9dfc60247e9ed3fc9c5cc7771543 -r9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f
--- firmware/App/Controllers/BloodFlow.c	(.../BloodFlow.c)	(revision 6f02ff4686ec9dfc60247e9ed3fc9c5cc7771543)
+++ firmware/App/Controllers/BloodFlow.c	(.../BloodFlow.c)	(revision 9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f)
@@ -150,6 +150,7 @@
 static OVERRIDE_F32_T bpFlowAlphaYIntercept;                                        ///< Blood flow estimation term for alpha Y intercept.
 static OVERRIDE_F32_T bpFlowWearATerm;                                              ///< Blood flow estimation term for wear slope.
 static OVERRIDE_F32_T bpFlowWearBTerm;                                              ///< Blood flow estimation term for wear offset.
+static OVERRIDE_F32_T bpStrokeVolumeMlPerRev;
 
 //static TD_PUMPS_CAL_RECORD_T bloodPumpCalRecord;                                    ///< Blood pump calibration record.
 
@@ -1433,4 +1434,21 @@
     return result;
 }
 
+/*********************************************************************//**
+* @brief
+* The testBPStrokeVolumeOverride function overrides the stroke volume
+* (mL per rotor revolution) used in the blood flow estimation equation.
+* @details \b Inputs: none
+* @details \b Outputs: bpStrokeVolumeMlPerRev
+* @param message Override message from Dialin which includes the stroke
+* volume (mL per rotor revolution) to override with.
+* @return TRUE if override successful, FALSE if not
+*************************************************************************/
+BOOL testBPStrokeVolumeOverride( MESSAGE_T *message )
+{
+    BOOL result = f32Override( message, &bpStrokeVolumeMlPerRev );
+
+    return result;
+}
+
 /**@}*/
Index: firmware/App/Controllers/BloodFlow.h
===================================================================
diff -u -r395522dffef1348e176564925656012f529c1910 -r9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f
--- firmware/App/Controllers/BloodFlow.h	(.../BloodFlow.h)	(revision 395522dffef1348e176564925656012f529c1910)
+++ firmware/App/Controllers/BloodFlow.h	(.../BloodFlow.h)	(revision 9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f)
@@ -87,6 +87,7 @@
 BOOL testBPFlowAlphaYInterceptOverride( MESSAGE_T *message );
 BOOL testBPFlowWearATermOverride( MESSAGE_T *message );
 BOOL testBPFlowWearBTermOverride( MESSAGE_T *message );
+BOOL testBPStrokeVolumeOverride( MESSAGE_T *message );
 
 /**@}*/
 
Index: firmware/App/Modes/StateTxBloodPrime.c
===================================================================
diff -u -r63fdc9a97e335c359fed989383cb56db57dc272f -r9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f
--- firmware/App/Modes/StateTxBloodPrime.c	(.../StateTxBloodPrime.c)	(revision 63fdc9a97e335c359fed989383cb56db57dc272f)
+++ firmware/App/Modes/StateTxBloodPrime.c	(.../StateTxBloodPrime.c)	(revision 9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f)
@@ -56,6 +56,9 @@
 /// Tubing portion of blood prime volume to prime the blood side circuit (in mL).
 #define TUBING_BLOOD_PRIME_VOLUME_ML               126
 
+///
+#define BLOOD_PRIME_PAUSE_TIMEOUT_SEC               ( 5 * SEC_PER_MIN )
+
 // ********** private data **********
 
 static BLOOD_PRIME_STATE_T bloodPrimeState;                                     ///< Current state of the blood prime sub-mode.
@@ -72,7 +75,7 @@
 static U32  bloodPrimePublishTimerCtr;                                          ///< Timer counter for determining interval for blood prime status to be published.
 static U32  lastBloodPrimeFlowRate_mL_min;                                      ///< Flow rate prior to pausing blood prime.
 static U32  requestedBloodFlowRate_mL_min;                                      ///< Requested blood flow rate from UI.
-static U32 bloodPrimeStartMS = 0;                                               ///< Start time of Blood Prime (ms timer count)
+static U32  bloodPrimeStartMS = 0;                                              ///< Start time of Blood Prime (ms timer count)
 
 /// Interval (in task intervals) at which to publish blood prime data to CAN bus.
 static OVERRIDE_U32_T bloodPrimePublishInterval = { BLOOD_PRIME_DATA_PUBLISH_INTERVAL, BLOOD_PRIME_DATA_PUBLISH_INTERVAL, BLOOD_PRIME_DATA_PUBLISH_INTERVAL, 0 };
@@ -120,7 +123,7 @@
         estRampSeconds = (F32)MIN_RAMP_TIME_SEC;
     }
     bloodPrimeRampStep_mL = rampRateSpan / estRampSeconds;
-    bloodPrimeStartMS = getMSTimerCount();
+    bloodPrimeStartMS = 0;
 }
 
 /*********************************************************************//**
@@ -275,6 +278,7 @@
         setValvePosition( H1_VALV, VALVE_POSITION_C_CLOSE );
         setValvePosition( H19_VALV, VALVE_POSITION_C_CLOSE );
         result = BLOOD_PRIME_PAUSED_STATE;
+        bloodPrimeStartMS = getMSTimerCount();
     }
     // When UI changes blood flow rate
     else if ( TRUE == pendingFlowChangeRequest )
@@ -332,6 +336,7 @@
         setValvePosition( H1_VALV, VALVE_POSITION_C_CLOSE );
         setValvePosition( H19_VALV, VALVE_POSITION_C_CLOSE );
         result = BLOOD_PRIME_PAUSED_STATE;
+        bloodPrimeStartMS = getMSTimerCount();
     }
     // When UI changes blood flow rate
     else if ( TRUE == pendingFlowChangeRequest )
@@ -503,10 +508,25 @@
         bloodPrimePublishTimerCtr = 0;
         data.targetBloodPrimeVolumeMl = bloodPrimeTargetVolume_mL;
         data.deliveredBloodPrimeVolumeMl = MAX( 0.0, getBloodPrimeVolume() );
-        elapsedMS = calcTimeSince( bloodPrimeStartMS );
-        elapsedSec = elapsedMS / 1000U;
-        data.bloodPrimeTimeoutSec = bloodPrimeStartMS;
-        data.bloodPrimeCountdownSec = elapsedSec;
+        if ( BLOOD_PRIME_PAUSED_STATE == bloodPrimeState )
+        {
+            elapsedMS = calcTimeSince( bloodPrimeStartMS );
+            elapsedSec = elapsedMS / MS_PER_SECOND;
+            data.bloodPrimeTimeoutSec = BLOOD_PRIME_PAUSE_TIMEOUT_SEC;
+            if ( elapsedSec < BLOOD_PRIME_PAUSE_TIMEOUT_SEC )
+            {
+                data.bloodPrimeCountdownSec = BLOOD_PRIME_PAUSE_TIMEOUT_SEC - elapsedSec;
+            }
+            else
+            {
+                data.bloodPrimeCountdownSec = 0;
+            }
+        }
+        else
+        {
+            data.bloodPrimeTimeoutSec = 0;
+            data.bloodPrimeCountdownSec = 0;
+        }
 
         broadcastData( MSG_ID_TD_BLOOD_PRIME_PROGRESS_DATA, COMM_BUFFER_OUT_CAN_TD_BROADCAST, (U08*)&data, sizeof( BLOOD_PRIME_DATA_PAYLOAD_T ) );
     }
Index: firmware/App/Services/Messaging.c
===================================================================
diff -u -rc01e44290174eb4098c14b17031ac538d7560b03 -r9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f
--- firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision c01e44290174eb4098c14b17031ac538d7560b03)
+++ firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision 9ee205a82fc3bb2b6cdf871a2ef506b7a6caf88f)
@@ -168,9 +168,9 @@
     { MSG_ID_TD_EJECTOR_PUBLISH_INTERVAL_OVERRIDE_REQUEST,              &testEjectorDataPublishIntervalOverride },
     { MSG_ID_TD_SET_AIR_TRAP_CONTROL,                                   &testSetAirTrapControl },
     { MSG_ID_TD_HOME_BLOOD_PUMP,                                        &testHomeBloodPump },
-    { MSG_ID_TD_BLOOD_FLOW_ALPHA_Y_INTERCEPT_OVERRIDE_REQUEST,          &testBPFlowAlphaYInterceptOverride },
     { MSG_ID_TD_BLOOD_FLOW_WEAR_A_TERM_OVERRIDE_REQUEST,                &testBPFlowWearATermOverride },
     { MSG_ID_TD_BLOOD_FLOW_WEAR_B_TERM_OVERRIDE_REQUEST,                &testBPFlowWearBTermOverride },
+    { MSG_ID_TD_BLOOD_FLOW_STROKE_VOLUME_OVERRIDE_REQUEST,              &testBPStrokeVolumeOverride },
     { MSG_ID_TD_SET_TEST_CONFIGURATION,                                 &testSetTestConfiguration },
     { MSG_ID_TD_GET_TEST_CONFIGURATION,                                 &testGetTestConfiguration },
     { MSG_ID_TD_RESET_ALL_TEST_CONFIGURATIONS,                          &testResetAllTestConfigurations },