Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -ra1a0187daedaf2c12e6f9eccfbf9e423d952e029 -r92f32196d272e32f9480e82dd09a038bb68753bc
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision a1a0187daedaf2c12e6f9eccfbf9e423d952e029)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 92f32196d272e32f9480e82dd09a038bb68753bc)
@@ -77,6 +77,10 @@
 /// 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
+static BOOL testCartridgesMode = FALSE; // Flag indicates we are testing cartridges.  Used only for cartridge test build.
+#endif
+
 // ********** private function prototypes **********
 
 static HD_STANDBY_STATE_T handleStandbyModeStartState( void );
@@ -231,6 +235,36 @@
             break;
     }
 
+#ifdef CARTRIDGE_TEST_BUILD
+    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;
+        }
+    }
+#endif
+
     return currentStandbyState;
 }