diff --git a/firmware/console/binary/tunerstudio.cpp b/firmware/console/binary/tunerstudio.cpp
index 6a911f854f..bf6a0b1b75 100644
--- a/firmware/console/binary/tunerstudio.cpp
+++ b/firmware/console/binary/tunerstudio.cpp
@@ -261,7 +261,8 @@ static const void * getStructAddr(live_data_e structId) {
 		return static_cast<idle_state_s*>(&engine->idle);
 	case LDS_TPS_ACCEL:
 		return static_cast<tps_accel_state_s*>(&engine->tpsAccelEnrichment);
-
+	case LDS_MAIN_RELAY:
+		return static_cast<main_relay_s*>(&engine->module<MainRelayController>().unmock());
 	default:
 		return nullptr;
 	}
diff --git a/firmware/controllers/actuators/main_relay.cpp b/firmware/controllers/actuators/main_relay.cpp
new file mode 100644
index 0000000000..d5d3bb3891
--- /dev/null
+++ b/firmware/controllers/actuators/main_relay.cpp
@@ -0,0 +1,17 @@
+#include "pch.h"
+
+#include "main_relay.h"
+
+void MainRelayController::onSlowCallback() {
+	isBenchTest = engine->isInMainRelayBench();
+
+#if EFI_MAIN_RELAY_CONTROL
+	hasIgnitionVoltage = Sensor::getOrZero(SensorType::BatteryVoltage) > 5;
+
+	mainRelayState = isBenchTest | hasIgnitionVoltage;
+#else // not EFI_MAIN_RELAY_CONTROL
+	mainRelayState = !isBenchTest;
+#endif
+
+	enginePins.mainRelay.setValue(mainRelayState);
+}
diff --git a/firmware/controllers/actuators/main_relay.h b/firmware/controllers/actuators/main_relay.h
new file mode 100644
index 0000000000..0443271cb9
--- /dev/null
+++ b/firmware/controllers/actuators/main_relay.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#include "engine_module.h"
+#include "main_relay_generated.h"
+
+struct MainRelayController : public EngineModule, public main_relay_s {
+	void onSlowCallback() override;
+};
diff --git a/firmware/controllers/actuators/main_relay.txt b/firmware/controllers/actuators/main_relay.txt
new file mode 100644
index 0000000000..73aeaa2f9f
--- /dev/null
+++ b/firmware/controllers/actuators/main_relay.txt
@@ -0,0 +1,5 @@
+struct_no_prefix main_relay_s
+	bit isBenchTest
+	bit hasIgnitionVoltage
+	bit mainRelayState
+end_struct
diff --git a/firmware/controllers/actuators/main_relay_generated.h b/firmware/controllers/actuators/main_relay_generated.h
new file mode 100644
index 0000000000..104f2d87bd
--- /dev/null
+++ b/firmware/controllers/actuators/main_relay_generated.h
@@ -0,0 +1,108 @@
+// this section was generated automatically by rusEFI tool ConfigDefinition.jar based on (unknown script) controllers/actuators/main_relay.txt Fri Nov 19 13:01:22 PST 2021
+// by class com.rusefi.output.CHeaderConsumer
+// begin
+#pragma once
+#include "rusefi_types.h"
+// start of main_relay_s
+struct main_relay_s {
+	/**
+	offset 0 bit 0 */
+	bool isBenchTest : 1;
+	/**
+	offset 0 bit 1 */
+	bool hasIgnitionVoltage : 1;
+	/**
+	offset 0 bit 2 */
+	bool mainRelayState : 1;
+	/**
+	offset 0 bit 3 */
+	bool unusedBit_3_3 : 1;
+	/**
+	offset 0 bit 4 */
+	bool unusedBit_3_4 : 1;
+	/**
+	offset 0 bit 5 */
+	bool unusedBit_3_5 : 1;
+	/**
+	offset 0 bit 6 */
+	bool unusedBit_3_6 : 1;
+	/**
+	offset 0 bit 7 */
+	bool unusedBit_3_7 : 1;
+	/**
+	offset 0 bit 8 */
+	bool unusedBit_3_8 : 1;
+	/**
+	offset 0 bit 9 */
+	bool unusedBit_3_9 : 1;
+	/**
+	offset 0 bit 10 */
+	bool unusedBit_3_10 : 1;
+	/**
+	offset 0 bit 11 */
+	bool unusedBit_3_11 : 1;
+	/**
+	offset 0 bit 12 */
+	bool unusedBit_3_12 : 1;
+	/**
+	offset 0 bit 13 */
+	bool unusedBit_3_13 : 1;
+	/**
+	offset 0 bit 14 */
+	bool unusedBit_3_14 : 1;
+	/**
+	offset 0 bit 15 */
+	bool unusedBit_3_15 : 1;
+	/**
+	offset 0 bit 16 */
+	bool unusedBit_3_16 : 1;
+	/**
+	offset 0 bit 17 */
+	bool unusedBit_3_17 : 1;
+	/**
+	offset 0 bit 18 */
+	bool unusedBit_3_18 : 1;
+	/**
+	offset 0 bit 19 */
+	bool unusedBit_3_19 : 1;
+	/**
+	offset 0 bit 20 */
+	bool unusedBit_3_20 : 1;
+	/**
+	offset 0 bit 21 */
+	bool unusedBit_3_21 : 1;
+	/**
+	offset 0 bit 22 */
+	bool unusedBit_3_22 : 1;
+	/**
+	offset 0 bit 23 */
+	bool unusedBit_3_23 : 1;
+	/**
+	offset 0 bit 24 */
+	bool unusedBit_3_24 : 1;
+	/**
+	offset 0 bit 25 */
+	bool unusedBit_3_25 : 1;
+	/**
+	offset 0 bit 26 */
+	bool unusedBit_3_26 : 1;
+	/**
+	offset 0 bit 27 */
+	bool unusedBit_3_27 : 1;
+	/**
+	offset 0 bit 28 */
+	bool unusedBit_3_28 : 1;
+	/**
+	offset 0 bit 29 */
+	bool unusedBit_3_29 : 1;
+	/**
+	offset 0 bit 30 */
+	bool unusedBit_3_30 : 1;
+	/**
+	offset 0 bit 31 */
+	bool unusedBit_3_31 : 1;
+	/** total size 4*/
+};
+
+// end
+// this section was generated automatically by rusEFI tool ConfigDefinition.jar based on (unknown script) controllers/actuators/main_relay.txt Fri Nov 19 13:01:22 PST 2021
diff --git a/firmware/controllers/algo/engine.cpp b/firmware/controllers/algo/engine.cpp
index 49806e334d..14ceee8e9b 100644
--- a/firmware/controllers/algo/engine.cpp
+++ b/firmware/controllers/algo/engine.cpp
@@ -538,7 +538,7 @@ bool Engine::isInMainRelayBench() {
 }
 
 bool Engine::isInShutdownMode() const {
-#if EFI_MAIN_RELAY_CONTROL
+#if EFI_MAIN_RELAY_CONTROL && EFI_PROD_CODE
 	// if we are in "ignition_on" mode and not in shutdown mode
 	if (stopEngineRequestTimeNt == 0 && ignitionOnTimeNt > 0) {
 		const float vBattThresholdOff = 5.0f;
diff --git a/firmware/controllers/algo/engine.h b/firmware/controllers/algo/engine.h
index 5e6e711fc6..4a4bf757f0 100644
--- a/firmware/controllers/algo/engine.h
+++ b/firmware/controllers/algo/engine.h
@@ -30,6 +30,7 @@
 #include "launch_control.h"
 #include "trigger_scheduler.h"
 #include "fuel_pump.h"
+#include "main_relay.h"
 #include "type_list.h"
 
 #ifndef EFI_UNIT_TEST
@@ -135,6 +136,7 @@ public:
 #endif // EFI_HPFP && EFI_ENGINE_CONTROL
 
 		FuelPumpController,
+		MainRelayController,
 		EngineModule // dummy placeholder so the previous entries can all have commas
 		> engineModules;
 
diff --git a/firmware/controllers/algo/live_data_ids.h b/firmware/controllers/algo/live_data_ids.h
index 836cf423ab..b56a4f1713 100644
--- a/firmware/controllers/algo/live_data_ids.h
+++ b/firmware/controllers/algo/live_data_ids.h
@@ -21,5 +21,6 @@ LDS_TRIGGER_STATE,
 LDS_AC_CONTROL,
 LDS_FUEL_PUMP,
 LDS_IDLE,
-LDS_TPS_ACCEL
+LDS_TPS_ACCEL,
+LDS_MAIN_RELAY,
 } live_data_e;
diff --git a/firmware/controllers/controllers.mk b/firmware/controllers/controllers.mk
index 446b944fc2..e05fe2bd69 100644
--- a/firmware/controllers/controllers.mk
+++ b/firmware/controllers/controllers.mk
@@ -21,6 +21,7 @@ CONTROLLERS_SRC_CPP = \
 	$(CONTROLLERS_DIR)/actuators/idle_thread_io.cpp \
 	$(CONTROLLERS_DIR)/actuators/idle_hardware.cpp \
 	$(CONTROLLERS_DIR)/actuators/idle_thread.cpp \
+	$(CONTROLLERS_DIR)/actuators/main_relay.cpp \
 	$(CONTROLLERS_DIR)/actuators/pwm_tester.cpp \
 	$(CONTROLLERS_DIR)/actuators/vvt.cpp \
 	$(CONTROLLERS_DIR)/actuators/gppwm/gppwm_channel.cpp \
diff --git a/firmware/controllers/core/fsio_core.h b/firmware/controllers/core/fsio_core.h
index 61c5c12a8f..ad499a0f7c 100644
--- a/firmware/controllers/core/fsio_core.h
+++ b/firmware/controllers/core/fsio_core.h
@@ -33,7 +33,6 @@ typedef enum {
 	LE_METHOD_RPM = 100,
 	LE_METHOD_COOLANT = 101,
 	LE_METHOD_FAN = 102,
-	LE_METHOD_TIME_SINCE_BOOT = 103,
 	LE_METHOD_TPS = 106,
 	LE_METHOD_MAF = 107,
 	LE_METHOD_INTAKE_AIR = 108,
@@ -52,7 +51,6 @@ typedef enum {
 	LE_METHOD_FSIO_DIGITAL_INPUT = 123,
 	LE_METHOD_FSIO_SETTING = 124,
 	LE_METHOD_PPS = 125,
-	LE_METHOD_IN_MR_BENCH = 128,
 	LE_METHOD_FUEL_FLOW_RATE = 131,
 	LE_METHOD_OIL_PRESSURE = 132,
 
diff --git a/firmware/controllers/core/fsio_impl.cpp b/firmware/controllers/core/fsio_impl.cpp
index be4f58b227..61156de81e 100644
--- a/firmware/controllers/core/fsio_impl.cpp
+++ b/firmware/controllers/core/fsio_impl.cpp
@@ -55,7 +55,6 @@ static LENameOrdinalPair leOilPressure(LE_METHOD_OIL_PRESSURE, "oilp");
 static LENameOrdinalPair leAcToggle(LE_METHOD_AC_TOGGLE, "ac_on_switch");
 // @returns float number of seconds since last A/C toggle
 static LENameOrdinalPair leTimeSinceAcToggle(LE_METHOD_TIME_SINCE_AC_TOGGLE, "time_since_ac_on_switch");
-static LENameOrdinalPair leTimeSinceBoot(LE_METHOD_TIME_SINCE_BOOT, "time_since_boot");
 static LENameOrdinalPair leFsioSetting(LE_METHOD_FSIO_SETTING, FSIO_METHOD_FSIO_SETTING);
 static LENameOrdinalPair leFsioAnalogInput(LE_METHOD_FSIO_ANALOG_INPUT, FSIO_METHOD_FSIO_ANALOG_INPUT);
 static LENameOrdinalPair leFsioDigitalInput(LE_METHOD_FSIO_DIGITAL_INPUT, FSIO_METHOD_FSIO_DIGITAL_INPUT);
@@ -63,7 +62,6 @@ static LENameOrdinalPair leIntakeVVT(LE_METHOD_INTAKE_VVT, "ivvt");
 static LENameOrdinalPair leExhaustVVT(LE_METHOD_EXHAUST_VVT, "evvt");
 static LENameOrdinalPair leCrankingRpm(LE_METHOD_CRANKING_RPM, "cranking_rpm");
 static LENameOrdinalPair leInShutdown(LE_METHOD_IN_SHUTDOWN, "in_shutdown");
-static LENameOrdinalPair leInMrBench(LE_METHOD_IN_MR_BENCH, "in_mr_bench");
 static LENameOrdinalPair leFuelRate(LE_METHOD_FUEL_FLOW_RATE, "fuel_flow");
 
 #include "fsio_names.def"
@@ -76,10 +74,6 @@ CCM_OPTIONAL LEElementPool sysPool(sysElements, SYS_ELEMENT_POOL_SIZE);
 
 static LEElement * starterRelayDisableLogic;
 
-#if EFI_MAIN_RELAY_CONTROL
-static LEElement * mainRelayLogic;
-#endif /* EFI_MAIN_RELAY_CONTROL */
-
 #if EFI_PROD_CODE || EFI_SIMULATOR
 
 FsioResult getEngineValue(le_action_e action) {
@@ -108,20 +102,10 @@ FsioResult getEngineValue(le_action_e action) {
 	case LE_METHOD_EXHAUST_VVT:
 		return engine->triggerCentral.getVVTPosition(0, 1);
 #endif
-	case LE_METHOD_TIME_SINCE_BOOT:
-#if EFI_MAIN_RELAY_CONTROL
-		// in main relay control mode, we return the number of seconds since the ignition is turned on
-		// (or negative if the ignition key is switched off)
-		return engine->getTimeIgnitionSeconds();
-#else
-		return getTimeNowSeconds();
-#endif /* EFI_MAIN_RELAY_CONTROL */
 	case LE_METHOD_CRANKING_RPM:
 		return engineConfiguration->cranking.rpm;
 	case LE_METHOD_IN_SHUTDOWN:
 		return engine->isInShutdownMode();
-	case LE_METHOD_IN_MR_BENCH:
-		return engine->isInMainRelayBench();
 	case LE_METHOD_VBATT:
 		return Sensor::getOrZero(SensorType::BatteryVoltage);
 	case LE_METHOD_TPS:
@@ -159,8 +143,6 @@ static const char * action2String(le_action_e action) {
 			return "fan";
 		case LE_METHOD_IN_SHUTDOWN:
 			return leInShutdown.name;
-		case LE_METHOD_IN_MR_BENCH:
-			return leInMrBench.name;
 #include "fsio_strings.def"
 
 		default: {
@@ -198,18 +180,6 @@ static void setPinState(const char * msg, OutputPin *pin, LEElement *element) {
  * this method should be invoked periodically to calculate FSIO and toggle corresponding FSIO outputs
  */
 void runFsio() {
-#if EFI_MAIN_RELAY_CONTROL
-	if (isBrainPinValid(engineConfiguration->mainRelayPin))
-		// the MAIN_RELAY_LOGIC calls engine->isInShutdownMode()
-		setPinState("main_relay", &enginePins.mainRelay, mainRelayLogic);
-#else /* EFI_MAIN_RELAY_CONTROL */
-	/**
-	 * main relay is always on if ECU is on, that's a good enough initial implementation
-	 */
-	if (isBrainPinValid(engineConfiguration->mainRelayPin))
-		enginePins.mainRelay.setValue(!engine->isInMainRelayBench());
-#endif /* EFI_MAIN_RELAY_CONTROL */
-
 	if (isBrainPinValid(engineConfiguration->starterRelayDisablePin))
 		setPinState("starter_relay", &enginePins.starterRelayDisable, starterRelayDisableLogic);
 
@@ -314,10 +284,6 @@ void initFsioImpl() {
 	sysPool.reset();
 #endif
 
-#if EFI_MAIN_RELAY_CONTROL
-	if (isBrainPinValid(engineConfiguration->mainRelayPin))
-		mainRelayLogic = sysPool.parseExpression(MAIN_RELAY_LOGIC);
-#endif /* EFI_MAIN_RELAY_CONTROL */
 	if (isBrainPinValid(engineConfiguration->starterRelayDisablePin))
 		starterRelayDisableLogic = sysPool.parseExpression(STARTER_RELAY_LOGIC);
 
@@ -342,10 +308,6 @@ void runHardcodedFsio() {
 	}
 #endif /* EFI_PROD_CODE */
 
-	// see MAIN_RELAY_LOGIC
-	if (isBrainPinValid(engineConfiguration->mainRelayPin)) {
-		enginePins.mainRelay.setValue((getTimeNowSeconds() < 2) || (Sensor::getOrZero(SensorType::BatteryVoltage) > LOW_VBATT) || engine->isInShutdownMode());
-	}
 	// see STARTER_RELAY_LOGIC
 	if (isBrainPinValid(engineConfiguration->starterRelayDisablePin)) {
 		enginePins.starterRelayDisable.setValue(engine->rpmCalculator.getRpm() < engineConfiguration->cranking.rpm);
diff --git a/firmware/controllers/engine_controller.cpp b/firmware/controllers/engine_controller.cpp
index 79b516f2c8..f3eb7d682b 100644
--- a/firmware/controllers/engine_controller.cpp
+++ b/firmware/controllers/engine_controller.cpp
@@ -750,7 +750,7 @@ void initEngineContoller() {
 #define RAM_UNUSED_SIZE 9000
 #endif
 #ifndef CCM_UNUSED_SIZE
-#define CCM_UNUSED_SIZE 32
+#define CCM_UNUSED_SIZE 16
 #endif
 static char UNUSED_RAM_SIZE[RAM_UNUSED_SIZE];
 static char UNUSED_CCM_SIZE[CCM_UNUSED_SIZE] CCM_OPTIONAL;
diff --git a/firmware/controllers/system_fsio.h b/firmware/controllers/system_fsio.h
index 30632eced4..feb2769f45 100644
--- a/firmware/controllers/system_fsio.h
+++ b/firmware/controllers/system_fsio.h
@@ -22,17 +22,6 @@
 
 // Human-readable: (rpm > fsio_setting(2)) | ((coolant > fsio_setting(3)) | (vbatt < fsio_setting(4)))
 #define COMBINED_WARNING_LIGHT "rpm 2 fsio_setting > coolant 3 fsio_setting > vbatt 4 fsio_setting < | |"
-//needed by EFI_MAIN_RELAY_CONTROL which is currently FALSE for most of the boards
-// todo: make '5' a setting?
-// todo: always have 'EFI_MAIN_RELAY_CONTROL'?
-// at the moment microRusEFI would not be happy with vbatt > 5 since microRusEFI senses main relay output
-// todo https://github.com/rusefi/rusefi/issues/2258
-//MAIN_RELAY_LOGIC=(time_since_boot >= 0 & time_since_boot < 2) | (vbatt > 5) | in_shutdown
-//MAIN_RELAY_LOGIC=(!in_mr_bench) & ((vbatt > 5) | in_shutdown)
-
-// Human-readable: (!in_mr_bench) & (vbatt > 5)
-#define MAIN_RELAY_LOGIC "in_mr_bench ! vbatt 5 > &"
-// could be used for simple variable intake geometry setups or warning light or starter block
 
 // Human-readable: rpm > fsio_setting(1)
 #define RPM_ABOVE_USER_SETTING_1 "rpm 1 fsio_setting >"
diff --git a/firmware/controllers/system_fsio.txt b/firmware/controllers/system_fsio.txt
index 55ea08f03d..862fc79e0d 100644
--- a/firmware/controllers/system_fsio.txt
+++ b/firmware/controllers/system_fsio.txt
@@ -14,15 +14,6 @@ TOO_HOT_LOGIC=coolant > 120
 # Combined RPM, CLT and VBATT warning light
 COMBINED_WARNING_LIGHT=(rpm > fsio_setting(2)) | ((coolant > fsio_setting(3)) | (vbatt < fsio_setting(4)))
 
-#needed by EFI_MAIN_RELAY_CONTROL which is currently FALSE for most of the boards
-# todo: make '5' a setting?
-# todo: always have 'EFI_MAIN_RELAY_CONTROL'?
-# at the moment microRusEFI would not be happy with vbatt > 5 since microRusEFI senses main relay output
-# todo https://github.com/rusefi/rusefi/issues/2258
-#MAIN_RELAY_LOGIC=(time_since_boot >= 0 & time_since_boot < 2) | (vbatt > 5) | in_shutdown
-#MAIN_RELAY_LOGIC=(!in_mr_bench) & ((vbatt > 5) | in_shutdown)
-MAIN_RELAY_LOGIC=(!in_mr_bench) & (vbatt > 5)
-
 # could be used for simple variable intake geometry setups or warning light or starter block
 RPM_ABOVE_USER_SETTING_1=rpm > fsio_setting(1)
 
diff --git a/firmware/gen_live_documentation.sh b/firmware/gen_live_documentation.sh
index 37ac10e41d..f92dcc616c 100755
--- a/firmware/gen_live_documentation.sh
+++ b/firmware/gen_live_documentation.sh
@@ -11,6 +11,9 @@ bash gen_live_documentation_one_file.sh ac_control AcControl.java controllers/ac
 bash gen_live_documentation_one_file.sh fuel_pump FuelPump.java controllers/actuators
 [ $? -eq 0 ] || { echo "ERROR generating"; exit 1; }
 
+bash gen_live_documentation_one_file.sh main_relay MainRelay.java controllers/actuators
+[ $? -eq 0 ] || { echo "ERROR generating"; exit 1; }
+
 bash gen_live_documentation_one_file.sh pid_state PidState.java util/math
 [ $? -eq 0 ] || { echo "ERROR generating"; exit 1; }
 
diff --git a/java_console/io/src/main/java/com/rusefi/enums/live_data_e.java b/java_console/io/src/main/java/com/rusefi/enums/live_data_e.java
index b87d877a8e..b5a6543df1 100644
--- a/java_console/io/src/main/java/com/rusefi/enums/live_data_e.java
+++ b/java_console/io/src/main/java/com/rusefi/enums/live_data_e.java
@@ -16,4 +16,5 @@ public enum live_data_e {
 	LDS_FUEL_PUMP,
 	LDS_IDLE,
 	LDS_TPS_ACCEL,
+	LDS_MAIN_RELAY,
 }
diff --git a/java_console/models/src/main/java/com/rusefi/config/generated/MainRelay.java b/java_console/models/src/main/java/com/rusefi/config/generated/MainRelay.java
new file mode 100644
index 0000000000..81cd71280c
--- /dev/null
+++ b/java_console/models/src/main/java/com/rusefi/config/generated/MainRelay.java
@@ -0,0 +1,75 @@
+package com.rusefi.config.generated;
+
+// this file was generated automatically by rusEFI tool ConfigDefinition.jar based on (unknown script) controllers/actuators/main_relay.txt Fri Nov 19 13:01:22 PST 2021
+
+// by class com.rusefi.output.FileJavaFieldsConsumer
+import com.rusefi.config.*;
+
+public class MainRelay {
+	public static final Field ISBENCHTEST = Field.create("ISBENCHTEST", 0, FieldType.BIT, 0);
+	public static final Field HASIGNITIONVOLTAGE = Field.create("HASIGNITIONVOLTAGE", 0, FieldType.BIT, 1);
+	public static final Field MAINRELAYSTATE = Field.create("MAINRELAYSTATE", 0, FieldType.BIT, 2);
+	public static final Field UNUSEDBIT_3_3 = Field.create("UNUSEDBIT_3_3", 0, FieldType.BIT, 3);
+	public static final Field UNUSEDBIT_3_4 = Field.create("UNUSEDBIT_3_4", 0, FieldType.BIT, 4);
+	public static final Field UNUSEDBIT_3_5 = Field.create("UNUSEDBIT_3_5", 0, FieldType.BIT, 5);
+	public static final Field UNUSEDBIT_3_6 = Field.create("UNUSEDBIT_3_6", 0, FieldType.BIT, 6);
+	public static final Field UNUSEDBIT_3_7 = Field.create("UNUSEDBIT_3_7", 0, FieldType.BIT, 7);
+	public static final Field UNUSEDBIT_3_8 = Field.create("UNUSEDBIT_3_8", 0, FieldType.BIT, 8);
+	public static final Field UNUSEDBIT_3_9 = Field.create("UNUSEDBIT_3_9", 0, FieldType.BIT, 9);
+	public static final Field UNUSEDBIT_3_10 = Field.create("UNUSEDBIT_3_10", 0, FieldType.BIT, 10);
+	public static final Field UNUSEDBIT_3_11 = Field.create("UNUSEDBIT_3_11", 0, FieldType.BIT, 11);
+	public static final Field UNUSEDBIT_3_12 = Field.create("UNUSEDBIT_3_12", 0, FieldType.BIT, 12);
+	public static final Field UNUSEDBIT_3_13 = Field.create("UNUSEDBIT_3_13", 0, FieldType.BIT, 13);
+	public static final Field UNUSEDBIT_3_14 = Field.create("UNUSEDBIT_3_14", 0, FieldType.BIT, 14);
+	public static final Field UNUSEDBIT_3_15 = Field.create("UNUSEDBIT_3_15", 0, FieldType.BIT, 15);
+	public static final Field UNUSEDBIT_3_16 = Field.create("UNUSEDBIT_3_16", 0, FieldType.BIT, 16);
+	public static final Field UNUSEDBIT_3_17 = Field.create("UNUSEDBIT_3_17", 0, FieldType.BIT, 17);
+	public static final Field UNUSEDBIT_3_18 = Field.create("UNUSEDBIT_3_18", 0, FieldType.BIT, 18);
+	public static final Field UNUSEDBIT_3_19 = Field.create("UNUSEDBIT_3_19", 0, FieldType.BIT, 19);
+	public static final Field UNUSEDBIT_3_20 = Field.create("UNUSEDBIT_3_20", 0, FieldType.BIT, 20);
+	public static final Field UNUSEDBIT_3_21 = Field.create("UNUSEDBIT_3_21", 0, FieldType.BIT, 21);
+	public static final Field UNUSEDBIT_3_22 = Field.create("UNUSEDBIT_3_22", 0, FieldType.BIT, 22);
+	public static final Field UNUSEDBIT_3_23 = Field.create("UNUSEDBIT_3_23", 0, FieldType.BIT, 23);
+	public static final Field UNUSEDBIT_3_24 = Field.create("UNUSEDBIT_3_24", 0, FieldType.BIT, 24);
+	public static final Field UNUSEDBIT_3_25 = Field.create("UNUSEDBIT_3_25", 0, FieldType.BIT, 25);
+	public static final Field UNUSEDBIT_3_26 = Field.create("UNUSEDBIT_3_26", 0, FieldType.BIT, 26);
+	public static final Field UNUSEDBIT_3_27 = Field.create("UNUSEDBIT_3_27", 0, FieldType.BIT, 27);
+	public static final Field UNUSEDBIT_3_28 = Field.create("UNUSEDBIT_3_28", 0, FieldType.BIT, 28);
+	public static final Field UNUSEDBIT_3_29 = Field.create("UNUSEDBIT_3_29", 0, FieldType.BIT, 29);
+	public static final Field UNUSEDBIT_3_30 = Field.create("UNUSEDBIT_3_30", 0, FieldType.BIT, 30);
+	public static final Field UNUSEDBIT_3_31 = Field.create("UNUSEDBIT_3_31", 0, FieldType.BIT, 31);
+	public static final Field[] VALUES = {
+	ISBENCHTEST,
+	HASIGNITIONVOLTAGE,
+	MAINRELAYSTATE,
+	UNUSEDBIT_3_3,
+	UNUSEDBIT_3_4,
+	UNUSEDBIT_3_5,
+	UNUSEDBIT_3_6,
+	UNUSEDBIT_3_7,
+	UNUSEDBIT_3_8,
+	UNUSEDBIT_3_9,
+	UNUSEDBIT_3_10,
+	UNUSEDBIT_3_11,
+	UNUSEDBIT_3_12,
+	UNUSEDBIT_3_13,
+	UNUSEDBIT_3_14,
+	UNUSEDBIT_3_15,
+	UNUSEDBIT_3_16,
+	UNUSEDBIT_3_17,
+	UNUSEDBIT_3_18,
+	UNUSEDBIT_3_19,
+	UNUSEDBIT_3_20,
+	UNUSEDBIT_3_21,
+	UNUSEDBIT_3_22,
+	UNUSEDBIT_3_23,
+	UNUSEDBIT_3_24,
+	UNUSEDBIT_3_25,
+	UNUSEDBIT_3_26,
+	UNUSEDBIT_3_27,
+	UNUSEDBIT_3_28,
+	UNUSEDBIT_3_29,
+	UNUSEDBIT_3_30,
+	UNUSEDBIT_3_31,
+	};
+}
diff --git a/java_console/ui/src/main/java/com/rusefi/livedata/LiveDataView.java b/java_console/ui/src/main/java/com/rusefi/livedata/LiveDataView.java
index 5f3dfd1d58..5bf66764e3 100644
--- a/java_console/ui/src/main/java/com/rusefi/livedata/LiveDataView.java
+++ b/java_console/ui/src/main/java/com/rusefi/livedata/LiveDataView.java
@@ -7,6 +7,7 @@ import com.rusefi.enums.live_data_e;
 public enum LiveDataView {
     AC_CONTROL(live_data_e.LDS_AC_CONTROL, AcControl.VALUES, "ac_control.cpp"),
     FUEL_PUMP(live_data_e.LDS_FUEL_PUMP, FuelPump.VALUES, "fuel_pump.cpp"),
+    MAIN_RELAY(live_data_e.LDS_MAIN_RELAY, MainRelay.VALUES, "main_relay.cpp"),
     TPS_ACCEL(live_data_e.LDS_TPS_ACCEL, TpsAccelState.VALUES, "accel_enrichment.cpp"),
     ;
 
diff --git a/unit_tests/efifeatures.h b/unit_tests/efifeatures.h
index d2c30fb3b5..05ea857c2f 100644
--- a/unit_tests/efifeatures.h
+++ b/unit_tests/efifeatures.h
@@ -74,3 +74,5 @@
 #define EFI_LUA TRUE
 
 #define EFI_HPFP TRUE
+
+#define EFI_MAIN_RELAY_CONTROL TRUE
diff --git a/unit_tests/tests/test_logic_expression.cpp b/unit_tests/tests/test_logic_expression.cpp
index 76608a6ec1..e8cc87bbf0 100644
--- a/unit_tests/tests/test_logic_expression.cpp
+++ b/unit_tests/tests/test_logic_expression.cpp
@@ -24,8 +24,6 @@ FsioResult getEngineValue(le_action_e action) {
 		return engine->fsioState.mockRpm;
 	case LE_METHOD_CRANKING_RPM:
 		return engine->fsioState.mockCrankingRpm;
-	case LE_METHOD_TIME_SINCE_BOOT:
-		return engine->fsioState.mockTimeSinceBoot;
 	case LE_METHOD_VBATT:
 		return 12;
 	case LE_METHOD_AC_TOGGLE:
diff --git a/unit_tests/tests/test_main_relay.cpp b/unit_tests/tests/test_main_relay.cpp
new file mode 100644
index 0000000000..542c43f69d
--- /dev/null
+++ b/unit_tests/tests/test_main_relay.cpp
@@ -0,0 +1,19 @@
+#include "pch.h"
+
+#include "main_relay.h"
+
+TEST(MainRelay, mr) {
+	EngineTestHelper eth(TEST_ENGINE);
+
+	MainRelayController dut;
+
+	// Low battery voltage, MR is off
+	Sensor::setMockValue(SensorType::BatteryVoltage, 1);
+	dut.onSlowCallback();
+	EXPECT_EQ(enginePins.mainRelay.getLogicValue(), false);
+
+	// Ignition is now on, MR is on
+	Sensor::setMockValue(SensorType::BatteryVoltage, 12);
+	dut.onSlowCallback();
+	EXPECT_EQ(enginePins.mainRelay.getLogicValue(), true);
+}
diff --git a/unit_tests/tests/tests.mk b/unit_tests/tests/tests.mk
index abebaa04f3..dfe9a7ba81 100644
--- a/unit_tests/tests/tests.mk
+++ b/unit_tests/tests/tests.mk
@@ -46,6 +46,7 @@ TESTS_SRC_CPP = \
 	tests/test_etb.cpp \
 	tests/test_dc_motor.cpp \
 	tests/test_fan_control.cpp \
+	tests/test_main_relay.cpp \
 	tests/test_vvt.cpp \
 	tests/test_launch.cpp \
 	tests/test_fuel_map.cpp \