Index: firmware/App/Modes/StateTxBloodPrime.c
===================================================================
diff -u -rf3271dd321c9d035ee2280618cf921f4f3e8017a -rcc925371f5081d8b486e65f942d9608e6e0b8d31
--- firmware/App/Modes/StateTxBloodPrime.c	(.../StateTxBloodPrime.c)	(revision f3271dd321c9d035ee2280618cf921f4f3e8017a)
+++ firmware/App/Modes/StateTxBloodPrime.c	(.../StateTxBloodPrime.c)	(revision cc925371f5081d8b486e65f942d9608e6e0b8d31)
@@ -26,6 +26,7 @@
 #include "StateTxBloodPrime.h"
 #include "Switches.h"
 #include "TaskGeneral.h"
+#include "Timers.h"
 #include "Utilities.h"
 #include "Valves.h"
 #include "Valve3Way.h"
@@ -71,6 +72,7 @@
 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)
 
 /// 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 };
@@ -118,6 +120,7 @@
         estRampSeconds = (F32)MIN_RAMP_TIME_SEC;
     }
     bloodPrimeRampStep_mL = rampRateSpan / estRampSeconds;
+    bloodPrimeStartMS = getMSTimerCount();
 }
 
 /*********************************************************************//**
@@ -494,10 +497,17 @@
     if ( ++bloodPrimePublishTimerCtr >= getU32OverrideValue( &bloodPrimePublishInterval ) )
     {
         BLOOD_PRIME_DATA_PAYLOAD_T data;
+        U32 elapsedMS;
+        U32 elapsedSec;
 
         bloodPrimePublishTimerCtr = 0;
         data.targetBloodPrimeVolumeMl = bloodPrimeTargetVolume_mL;
         data.deliveredBloodPrimeVolumeMl = MAX( 0.0, getBloodPrimeVolume() );
+        elapsedMS = calcTimeSince( bloodPrimeStartMS );
+        elapsedSec = elapsedMS / 1000U;
+        data.bloodPrimeTimeoutSec = bloodPrimeStartMS;
+        data.bloodPrimeCountdownSec = elapsedSec;
+
         broadcastData( MSG_ID_TD_BLOOD_PRIME_PROGRESS_DATA, COMM_BUFFER_OUT_CAN_TD_BROADCAST, (U08*)&data, sizeof( BLOOD_PRIME_DATA_PAYLOAD_T ) );
     }
 }