Index: firmware/App/Services/Messaging.c
===================================================================
diff -u -r91685a2616bc603aaa3d01206e27ac0b0fd02b45 -r1c478c1aff953528127767db1f4f747a7f7089c8
--- firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision 91685a2616bc603aaa3d01206e27ac0b0fd02b45)
+++ firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision 1c478c1aff953528127767db1f4f747a7f7089c8)
@@ -59,6 +59,7 @@
 #include "StateFlushFilterDefeatured.h"
 #include "StateFlushPermeate.h"
 #include "StateInletPressureCheck.h"
+#include "SubstitutionPump.h"
 #include "SystemCommDD.h"
 #include "Temperature.h"
 #include "TestSupport.h"
@@ -288,6 +289,7 @@
     { MSG_ID_FP_CONDUCTIVITY_SENSOR_VERSION_REQUEST,                                &testHandleConductivitySensorVersionRequest },
     { MSG_ID_DD_TEMPERATURE_SENSOR_FILTERED_TEMP_OVERRIDE_REQUEST,                  &testDDTemperatureSensorFilteredReadingsOverride },
     { MSG_ID_FP_SET_RECOVERY_VALVES_REQUEST,                                        &testIOFPSetValveRecoveryConfig },
+    { MSG_ID_DD_SUBSTITUTION_PUMP_START_STOP_OVERRIDE_REQUEST,                      &testSubstitutionPumpStartStopOverride },
 };
 
 /// Calculation for number of entries in the incoming message function handler look-up table.