oil pressure protection (while running)

firmware/controllers/algo/defaults/default_base_engine.cpp

@@ -109,6 +109,9 @@ void setDefaultBaseEngine() {
 
 	setDefaultVrThresholds();
 
+	// Oil pressure protection
+	engineConfiguration->minimumOilPressureTimeout = 0.5f;
+	setLinearCurve(config->minimumOilPressureBins, 0, 7000);
 }
 
 void setPPSInputs(adc_channel_e pps1, adc_channel_e pps2) {

firmware/controllers/engine_controller.cpp

@@ -664,6 +664,10 @@ bool validateConfig() {
 	}
 #endif
 
+	if (engineConfiguration->enableOilPressureProtect) {
+		ensureArrayIsAscending("Oil pressure protection", config->minimumOilPressureBins);
+	}
+
 	return true;
 }
 

firmware/controllers/limp_manager.cpp

@@ -111,17 +111,17 @@ void LimpManager::updateState(int rpm, efitick_t nowNt) {
 	}
 #if EFI_SHAFT_POSITION_INPUT
 	if (engine->rpmCalculator.isRunning()) {
+		bool hasOilpSensor = Sensor::hasSensor(SensorType::OilPressure);
+		auto oilp = Sensor::get(SensorType::OilPressure);
 		uint16_t minOilPressure = engineConfiguration->minOilPressureAfterStart;
 
 		// Only check if the setting is enabled and you have an oil pressure sensor
-		if (minOilPressure > 0 && Sensor::hasSensor(SensorType::OilPressure)) {
+		if (minOilPressure > 0 && hasOilpSensor) {
 			// Has it been long enough we should have pressure?
 			bool isTimedOut = engine->rpmCalculator.getSecondsSinceEngineStart(nowNt) > 5.0f;
 
 			// Only check before timed out
 			if (!isTimedOut) {
-				auto oilp = Sensor::get(SensorType::OilPressure);
-
 				if (oilp) {
 					// We had oil pressure! Set the flag.
 					if (oilp.Value > minOilPressure) {
@@ -135,9 +135,23 @@ void LimpManager::updateState(int rpm, efitick_t nowNt) {
 				allowFuel.clear(ClearReason::OilPressure);
 			}
 		}
+
+		if (oilp && engineConfiguration->enableOilPressureProtect) {
+			float minPressure = interpolate2d(rpm, config->minimumOilPressureBins, config->minimumOilPressureValues);
+			bool isPressureSufficient = oilp.Value > minPressure;
+
+			if (isPressureSufficient) {
+				m_lowOilPressureTimer.reset(nowNt);
+			}
+
+			if (m_lowOilPressureTimer.hasElapsedSec(engineConfiguration->minimumOilPressureTimeout)) {
+				allowFuel.clear(ClearReason::OilPressure);
+			}
+		}
 	} else {
 		// reset state in case of stalled engine
 		m_hadOilPressureAfterStart = false;
+		m_lowOilPressureTimer.reset(nowNt);
 	}
 
 	// If we're in engine stop mode, inhibit fuel

firmware/controllers/limp_manager.h

@@ -157,6 +157,9 @@ class LimpManager : public EngineModule {
 
 	// Tracks how long injector duty has been over the sustained limit
 	Timer m_injectorDutySustainedTimer;
+
+	// Tracks how long oil pressure has been below threshold
+	Timer m_lowOilPressureTimer;
 };
 
 LimpManager * getLimpManager();

firmware/integration/rusefi_config.txt

@@ -779,7 +779,7 @@ custom uart_device_e 1 bits, U08, @OFFSET@, [0:1], "Off", "UART1", "UART2", "UAR
 	pin_output_mode_e acRelayPinMode;
 	output_pin_e acRelayPin;
 
-	uint8_t unused754
+	uint8_t autoscale minimumOilPressureTimeout;Delay before cutting fuel due to low oil pressure. Use this to ignore short pressure blips and sensor noise.;"sec", 0.1, 0, 0, 5, 1
 
 	spi_device_e drv8860spiDevice;
 
@@ -826,7 +826,7 @@ sensor_chart_e sensorChartMode;rusEFI console Sensor Sniffer mode;
 	bit enableLaunchRetard
 	bit enableCanVss;Read VSS from OEM CAN bus according to selected CAN vehicle configuration.
 	bit enableInnovateLC2
-	bit unused808b7
+	bit enableOilPressureProtect
 	bit stftIgnoreErrorMagnitude;If enabled, adjust at a constant rate instead of a rate proportional to the current lambda error. This mode may be easier to tune, and more tolerant of sensor noise.
 	bit enableSoftwareKnock
 	bit verboseVVTDecoding;Verbose info in console below engineSnifferRpmThreshold\nenable vvt_details
@@ -1731,6 +1731,9 @@ uint8_t[FUEL_LEVEL_TABLE_COUNT] fuelLevelValues;;"%", 1, 0, 0, 100, 0
 uint8_t[DWELL_CURVE_SIZE] autoscale dwellVoltageCorrVoltBins;;"volts", 0.1, 0, 0, 20, 1
 uint8_t[DWELL_CURVE_SIZE] autoscale dwellVoltageCorrValues;;"multiplier", 0.02, 0, 0, 5, 2
 
+uint8_t[8] autoscale minimumOilPressureBins;;"RPM", 100, 0, 0, 25000, 0
+uint8_t[8] autoscale minimumOilPressureValues;;"kPa", 10, 0, 0, 1000, 0
+
 end_struct
 
 ! Pedal Position Sensor

firmware/tunerstudio/tunerstudio.template.ini

@@ -800,6 +800,14 @@ curve = 32Curve, "3-2 Shift Solenoid Percent by Speed"
 		yBins = throttleEstimateEffectiveAreaValues
 		gauge = TPSGauge
 
+	curve = minimumOilPressure, "Minimum oil pressure"
+		columnLabel = "RPM", "min pressure"
+		xAxis = 0, 8000, 9
+		yAxis = 0, 500, 6
+		xBins = minimumOilPressureBins, RPMValue
+		yBins = minimumOilPressureValues
+		gauge = OilPressGauge
+
 [TableEditor]
 	;		table_id,	map3d_id,	"title",		page
 
@@ -3805,6 +3813,9 @@ cmd_set_engine_type_default					= "@@TS_IO_TEST_COMMAND_char@@@@ts_command_e_TS_
 
 	dialog = oilPressureProtection, "Oil pressure protection"
 		field = "Minimum oil pressure after start",		minOilPressureAfterStart
+		field = "Enable low oil pressure protection",	enableOilPressureProtect
+		field = "Oil pressure protection timeout", 		minimumOilPressureTimeout
+		panel = minimumOilPressure
 
 	dialog = etbLimits, "Electronic Throttle Limiting"
 		field = "Smoothly close the throttle to limit RPM."

unit_tests/tests/test_limp.cpp

@@ -132,7 +132,7 @@ TEST(limp, boostCut) {
 	EXPECT_TRUE(dut.allowInjection());
 }
 
-TEST(limp, oilPressureFailureCase) {
+TEST(limp, oilPressureStartupFailureCase) {
 	EngineTestHelper eth(engine_type_e::TEST_ENGINE);
 	engineConfiguration->minOilPressureAfterStart = 200;
 
@@ -165,7 +165,7 @@ TEST(limp, oilPressureFailureCase) {
 	ASSERT_FALSE(dut.allowInjection());
 }
 
-TEST(limp, oilPressureSuccessCase) {
+TEST(limp, oilPressureStartupSuccessCase) {
 	EngineTestHelper eth(engine_type_e::TEST_ENGINE);
 	engineConfiguration->minOilPressureAfterStart = 200;
 
@@ -202,3 +202,45 @@ TEST(limp, oilPressureSuccessCase) {
 	dut.updateState(1000, getTimeNowNt());
 	ASSERT_TRUE(dut.allowInjection());
 }
+
+TEST(limp, oilPressureRunning) {
+	EngineTestHelper eth(engine_type_e::TEST_ENGINE);
+	engineConfiguration->enableOilPressureProtect = true;
+	engineConfiguration->minimumOilPressureTimeout = 1.0f;
+	setArrayValues(config->minimumOilPressureValues, 100);
+
+	LimpManager dut;
+
+	// Oil pressure starts OK
+	Sensor::setMockValue(SensorType::OilPressure, 110);
+
+	// Start the engine
+	engine->rpmCalculator.setRpmValue(1000);
+
+	// update & check: injection should be allowed
+	dut.updateState(1000, getTimeNowNt());
+	EXPECT_TRUE(dut.allowInjection());
+
+	// A long time later, everything should still be OK
+	advanceTimeUs(60e6);
+	dut.updateState(1000, getTimeNowNt());
+	EXPECT_TRUE(dut.allowInjection());
+
+	// Now oil pressure drops below threshold
+	Sensor::setMockValue(SensorType::OilPressure, 90);
+
+	// 0.9 second later, injection should continue as timeout isn't hit yet
+	advanceTimeUs(0.9e6);
+	dut.updateState(1000, getTimeNowNt());
+	ASSERT_TRUE(dut.allowInjection());
+
+	// 0.2 second later (1.1s since low pressure starts), injection should cut
+	advanceTimeUs(1.0e6);
+	dut.updateState(1000, getTimeNowNt());
+	ASSERT_FALSE(dut.allowInjection());
+
+	// Oil pressure is restored, and fuel should be restored too
+	Sensor::setMockValue(SensorType::OilPressure, 110);
+	dut.updateState(1000, getTimeNowNt());
+	ASSERT_TRUE(dut.allowInjection());
+}