diff --git a/McZapkie/MOVER.h b/McZapkie/MOVER.h
index 199c65a0..825bec6d 100644
--- a/McZapkie/MOVER.h
+++ b/McZapkie/MOVER.h
@@ -1943,6 +1943,7 @@ class TMoverParameters
 	double MirrorVelClose{5.0};
 	bool MirrorForbidden{false}; /*czy jest pozwolenie na otworzenie lusterek (przycisk)*/
 	bool ScndS = false; /*Czy jest bocznikowanie na szeregowej*/
+	bool ScndCtrlResistiveLock{false}; // the shunt controller can't be moved up while the master controller is at zero or on a resistive position (ScndCtrlResistiveLock=Yes in Cntrl.)
 	bool SpeedCtrl = false; /*czy jest tempomat*/
 	speed_control SpeedCtrlUnit; /*parametry tempomatu*/
 	double SpeedCtrlButtons[10]{30, 40, 50, 60, 70, 80, 90, 100, 110, 120}; /*przyciski prędkości*/
@@ -2372,6 +2373,8 @@ class TMoverParameters
 	bool IncScndCtrl(int CtrlSpeed);
 	bool DecScndCtrl(int CtrlSpeed);
 	int GetVirtualScndPos() const;
+	// whether ScndCtrlResistiveLock keeps the shunt controller from being moved up at the current master controller position
+	bool IsScndCtrlLockedByMainCtrl() const;
 	bool IsScndCtrlNoPowerPos() const;
 	bool IsScndCtrlMaxPowerPos() const;
 
diff --git a/McZapkie/Mover.cpp b/McZapkie/Mover.cpp
index 330e8eb8..b9d18d0b 100644
--- a/McZapkie/Mover.cpp
+++ b/McZapkie/Mover.cpp
@@ -2751,7 +2751,7 @@ bool TMoverParameters::IncScndCtrl(int CtrlSpeed)
 	{
 		//     if (RList[MainCtrlPos].R=0) and (MainCtrlPos>0) and (ScndCtrlPos<ScndCtrlPosNo) and
 		//     (not CoupledCtrl) then
-		if (ScndCtrlPos < ScndCtrlPosNo && !CoupledCtrl)
+		if (ScndCtrlPos < ScndCtrlPosNo && !CoupledCtrl && !IsScndCtrlLockedByMainCtrl())
 		{
 			// TBD, TODO: refactor this validation as part of relay check routine (currently in tractionforce()
 			// TBD, TODO: diesel electric engine utilize scndctrlactualpos like the other types?
@@ -2872,6 +2872,12 @@ bool TMoverParameters::DecScndCtrl(int CtrlSpeed)
 	return OK;
 }
 
+bool TMoverParameters::IsScndCtrlLockedByMainCtrl() const
+{
+	// ET21, ET22, EP09: the field shunting engages only on the resistance-free positions of the master controller (eu07/maszyna#402)
+	return ScndCtrlResistiveLock && (IsMainCtrlNoPowerPos() || RList[MainCtrlPos].R >= 0.01);
+}
+
 int TMoverParameters::GetVirtualScndPos() const
 {
 	if (TrainType == dt_ET42 && DynamicBrakeFlag && !ScndCtrlPos)
@@ -10897,6 +10903,7 @@ void TMoverParameters::LoadFIZ_Cntrl(std::string const &line)
 	extract_value(EIMCtrlEmergency, "EIMCtrlEmergency", line, "");
 
 	extract_value(ScndS, "ScndS", line, ""); // brak pozycji rownoleglej przy niskiej nastawie PSR
+	extract_value(ScndCtrlResistiveLock, "ScndCtrlResistiveLock", line, ""); // bocznikowanie tylko na pozycjach bezoporowych
 
 	extract_value(InitialCtrlDelay, "IniCDelay", line, "");
 	extract_value(CtrlDelay, "SCDelay", line, "");
diff --git a/tests/unit/test_cntrl.cpp b/tests/unit/test_cntrl.cpp
index 0dd3ddc2..43c983ed 100644
--- a/tests/unit/test_cntrl.cpp
+++ b/tests/unit/test_cntrl.cpp
@@ -37,3 +37,83 @@ TEST_CASE("cntrl: the relays of a multiple unit start on their own, of other veh
 		CHECK(unit->ConverterOverloadRelayStart == start_t::automatic);
 	}
 }
+
+namespace {
+
+// the first position of the master controller after Position without the starting resistors in the circuit
+int resistance_free_position(TMoverParameters const &Vehicle, int Position = 0) {
+	for (auto position{Position + 1}; position <= Vehicle.MainCtrlPosNo; ++position) {
+		if (Vehicle.RList[position].R < 0.01) {
+			return position;
+		}
+	}
+	return 0;
+}
+
+// the vehicle with its cab occupied, the master controller set to Position and the shunt controller off
+void controllers_at(vehicle &Vehicle, int Position) {
+	Vehicle->CabActive = 1;
+	Vehicle->MainCtrlPos = Position;
+	Vehicle->ScndCtrlPos = 0;
+}
+
+} // namespace
+
+TEST_CASE("cntrl: ScndCtrlResistiveLock keeps the field shunting off at zero and on the resistive positions (eu07/maszyna#402)") {
+	for (auto const *path : {"et22_v3/201e-rn", "ep09_v2/104e"}) {
+		CAPTURE(path);
+		vehicle locked{definition::fiz(path).set("Cntrl", "ScndCtrlResistiveLock", "Yes"), 0.0, "test", 1};
+		REQUIRE(locked->ScndCtrlResistiveLock);
+		REQUIRE(locked->ScndCtrlPosNo > 0);
+		auto const resistancefree{resistance_free_position(locked.mover())};
+		REQUIRE(resistancefree > 1);
+		REQUIRE(locked->RList[resistancefree - 1].R >= 0.01);
+
+		SUBCASE("zero") {
+			controllers_at(locked, 0);
+			CHECK(locked->IsScndCtrlLockedByMainCtrl());
+			CHECK_FALSE(locked->IncScndCtrl(1));
+			CHECK_FALSE(locked->IncScndCtrl(2));
+			CHECK(locked->ScndCtrlPos == 0);
+		}
+		SUBCASE("resistive positions") {
+			for (auto position{1}; position < resistancefree; ++position) {
+				CAPTURE(position);
+				controllers_at(locked, position);
+				CHECK_FALSE(locked->IncScndCtrl(1));
+				CHECK(locked->ScndCtrlPos == 0);
+			}
+		}
+		SUBCASE("every resistance-free position") {
+			for (auto position{resistancefree}; position > 0; position = resistance_free_position(locked.mover(), position)) {
+				CAPTURE(position);
+				controllers_at(locked, position);
+				CHECK_FALSE(locked->IsScndCtrlLockedByMainCtrl());
+				CHECK(locked->IncScndCtrl(1));
+				CHECK(locked->ScndCtrlPos == 1);
+			}
+		}
+		SUBCASE("the shunting still goes off on a resistive position") {
+			controllers_at(locked, resistancefree);
+			REQUIRE(locked->IncScndCtrl(1));
+			locked->MainCtrlPos = resistancefree - 1;
+			CHECK(locked->DecScndCtrl(1));
+			CHECK(locked->ScndCtrlPos == 0);
+		}
+	}
+}
+
+TEST_CASE("cntrl: without ScndCtrlResistiveLock the field shunting engages on any position, as before") {
+	for (auto const *path : {"et22_v3/201e-rn", "ep09_v2/104e"}) {
+		CAPTURE(path);
+		vehicle unlocked{definition::fiz(path), 0.0, "test", 1};
+		CHECK_FALSE(unlocked->ScndCtrlResistiveLock);
+		for (auto const position : {0, 1}) {
+			CAPTURE(position);
+			controllers_at(unlocked, position);
+			CHECK_FALSE(unlocked->IsScndCtrlLockedByMainCtrl());
+			CHECK(unlocked->IncScndCtrl(1));
+			CHECK(unlocked->ScndCtrlPos == 1);
+		}
+	}
+}
diff --git a/vehicle/Driver.cpp b/vehicle/Driver.cpp
index 08f0c0d2..bb6ff823 100644
--- a/vehicle/Driver.cpp
+++ b/vehicle/Driver.cpp
@@ -3364,7 +3364,7 @@ bool TController::IncSpeed()
 			                            mvOccupied->Vel <= (IsCargoTrain ? 40 : 30) + (seriesmodefieldshunting ? 5 : 0) - (fAccGravity < -0.025 ? 10 : 0));
 			// when not in series mode use the first available parallel mode configuration until 50/60 km/h for passenger/cargo train
 			// (if there's only one parallel mode configuration it'll be used regardless of current speed)
-			auto const usefieldshunting = mvControlling->StLinFlag && mvControlling->RList[mvControlling->MainCtrlPos].R < 0.01 &&
+			auto const usefieldshunting = mvControlling->StLinFlag && mvControlling->RList[mvControlling->MainCtrlPos].R < 0.01 && false == mvControlling->IsScndCtrlLockedByMainCtrl() &&
 			                              (useseriesmode ? mvControlling->RList[mvControlling->MainCtrlPos].Bn == 1 :
 			                               true == sufficientacceleration && true == sufficienttractionforce && mvOccupied->Vel <= (IsCargoTrain ? 60 : 50) + (parallelmodefieldshunting ? 5 : 0) ?
 			                                               mvControlling->RList[mvControlling->MainCtrlPos].Bn > 1 :