Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r42c6233847246407d81549a66458b12d3e3a27ac -rfb714597ad515d3774d69b94808f065788504724
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 42c6233847246407d81549a66458b12d3e3a27ac)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision fb714597ad515d3774d69b94808f065788504724)
@@ -77,6 +77,12 @@
 /// Interval (in task intervals) at which to publish standby mode data to CAN bus.
 static OVERRIDE_U32_T standbyModePublishInterval = { DISINFECTS_DATA_PUB_INTERVAL, DISINFECTS_DATA_PUB_INTERVAL, DISINFECTS_DATA_PUB_INTERVAL, 0 };
 
+#ifdef CARTRIDGE_TEST_BUILD  // Variables and definitions used only for cartridge test build.
+#define CARTRIDGE_TEST_COMPLETE_TIME        ( ( 10 * MIN_PER_HOUR * SEC_PER_MIN * MS_PER_SECOND ) / TASK_GENERAL_INTERVAL )
+static BOOL testCartridgesMode     = FALSE; // Flag indicates we are testing cartridges.
+static U32  testCartridgesTimerCtr = 0;     // Test timer counter.
+#endif
+
 // ********** private function prototypes **********
 
 static HD_STANDBY_STATE_T handleStandbyModeStartState( void );
@@ -231,6 +237,49 @@
             break;
     }
 
+#ifdef CARTRIDGE_TEST_BUILD
+    if ( TRUE == testCartridgesMode )
+    {
+        if ( ++testCartridgesTimerCtr >= CARTRIDGE_TEST_COMPLETE_TIME )
+        {
+            stop = TRUE;  // Stop cartridge test after 10 hrs
+        }
+        if ( TRUE == isAlarmActive( ALARM_ID_HD_FLUID_LEAK_DETECTED ) )
+        {
+            stop = TRUE;  // Stop cartridge test if a fluid leak is detected
+        }
+    }
+
+    if ( TRUE == stop )
+    {
+        if ( testCartridgesMode != TRUE )
+        {
+            testSetBloodPumpTargetDutyCycle( 0.652F );
+            testSetDialInPumpTargetDutyCycle( 0.701F );
+            testSetDialOutPumpTargetDutyCycle( 0.566F );
+            setValvePosition( VDI, VALVE_POSITION_B_OPEN );
+            setValvePosition( VDO, VALVE_POSITION_B_OPEN );
+            setValvePosition( VBA, VALVE_POSITION_B_OPEN );
+            setValvePosition( VBV, VALVE_POSITION_B_OPEN );
+            setValveAirTrap( STATE_CLOSED );
+            testCartridgesMode = TRUE;
+        }
+        else
+        {
+            signalBloodPumpHardStop();
+            signalDialInPumpHardStop();
+            signalDialOutPumpHardStop();
+            setValvePosition( VDI, VALVE_POSITION_A_INSERT_EJECT );
+            setValvePosition( VDO, VALVE_POSITION_A_INSERT_EJECT );
+            setValvePosition( VBA, VALVE_POSITION_A_INSERT_EJECT );
+            setValvePosition( VBV, VALVE_POSITION_A_INSERT_EJECT );
+            setValveAirTrap( STATE_OPEN );
+            testCartridgesMode = FALSE;
+            testCartridgesTimerCtr = 0;
+        }
+    }
+#endif
+
     return currentStandbyState;
 }