diff --git a/firmware/controllers/algo/obd_error_codes.h b/firmware/controllers/algo/obd_error_codes.h
index 8e8e34229d..5094c787ef 100644
--- a/firmware/controllers/algo/obd_error_codes.h
+++ b/firmware/controllers/algo/obd_error_codes.h
@@ -242,18 +242,18 @@ typedef enum {
 	//P0199 Engine Oil Temperature Sensor Intermittent
 	//DTC Codes - P0200-P0299 - Fuel and Air Metering (Injector Circuit)
 	//P0200 Injector Circuit Malfunction
-	//P0201 Injector Circuit Malfunction - Cylinder 1
-	//P0202 Injector Circuit Malfunction - Cylinder 2
-	//P0203 Injector Circuit Malfunction - Cylinder 3
-	//P0204 Injector Circuit Malfunction - Cylinder 4
-	//P0205 Injector Circuit Malfunction - Cylinder 5
-	//P0206 Injector Circuit Malfunction - Cylinder 6
-	//P0207 Injector Circuit Malfunction - Cylinder 7
-	//P0208 Injector Circuit Malfunction - Cylinder 8
-	//P0209 Injector Circuit Malfunction - Cylinder 9
-	//P0210 Injector Circuit Malfunction - Cylinder 10
-	//P0211 Injector Circuit Malfunction - Cylinder 11
-	//P0212 Injector Circuit Malfunction - Cylinder 12
+	OBD_Injector_Circuit_1 = 201,
+	OBD_Injector_Circuit_2 = 202,
+	OBD_Injector_Circuit_3 = 203,
+	OBD_Injector_Circuit_4 = 204,
+	OBD_Injector_Circuit_5 = 205,
+	OBD_Injector_Circuit_6 = 206,
+	OBD_Injector_Circuit_7 = 207,
+	OBD_Injector_Circuit_8 = 208,
+	OBD_Injector_Circuit_9 = 209,
+	OBD_Injector_Circuit_10 = 210,
+	OBD_Injector_Circuit_11 = 211,
+	OBD_Injector_Circuit_12 = 212,
 	//P0213 Cold Start Injector 1 Malfunction
 	//P0214 Cold Start Injector 2 Malfunction
 	//P0215 Engine Shutoff Solenoid Malfunction
@@ -401,18 +401,18 @@ typedef enum {
 	//P0348 Camshaft Position Sensor A Circuit High Input (Bank 2)
 	//P0349 Camshaft Position Sensor A Circuit Intermittent (Bank 2)
 	//P0350 Ignition Coil Primary/Secondary Circuit Malfunction
-	//P0351 Ignition Coil A Primary/Secondary Circuit Malfunction
-	//P0352 Ignition Coil B Primary/Secondary Circuit Malfunction
-	//P0353 Ignition Coil C Primary/Secondary Circuit Malfunction
-	//P0354 Ignition Coil D Primary/Secondary Circuit Malfunction
-	//P0355 Ignition Coil E Primary/Secondary Circuit Malfunction
-	//P0356 Ignition Coil F Primary/Secondary Circuit Malfunction
-	//P0357 Ignition Coil G Primary/Secondary Circuit Malfunction
-	//P0358 Ignition Coil H Primary/Secondary Circuit Malfunction
-	//P0359 Ignition Coil I Primary/Secondary Circuit Malfunction
-	//P0360 Ignition Coil J Primary/Secondary Circuit Malfunction
-	//P0361 Ignition Coil K Primary/Secondary Circuit Malfunction
-	//P0362 Ignition Coil L Primary/Secondary Circuit Malfunction
+	OBD_Ignition_Circuit_1 = 351,
+	OBD_Ignition_Circuit_2 = 352,
+	OBD_Ignition_Circuit_3 = 353,
+	OBD_Ignition_Circuit_4 = 354,
+	OBD_Ignition_Circuit_5 = 355,
+	OBD_Ignition_Circuit_6 = 356,
+	OBD_Ignition_Circuit_7 = 357,
+	OBD_Ignition_Circuit_8 = 358,
+	OBD_Ignition_Circuit_9 = 359,
+	OBD_Ignition_Circuit_10 = 360,
+	OBD_Ignition_Circuit_11 = 361,
+	OBD_Ignition_Circuit_12 = 362,
 	//P0363 Misfire Detected - Fueling Disabled
 	//P0364 Reserved
 	//P0365 Camshaft Position Sensor "B" Circuit (Bank 1)
diff --git a/firmware/controllers/bench_test.cpp b/firmware/controllers/bench_test.cpp
index df9972da51..d4c7689701 100644
--- a/firmware/controllers/bench_test.cpp
+++ b/firmware/controllers/bench_test.cpp
@@ -37,7 +37,6 @@
 #include "malfunction_central.h"
 #include "trigger_emulator_algo.h"
 #include "microsecond_timer.h"
-#include "gpio_ext.h"
 
 #if EFI_WIDEBAND_FIRMWARE_UPDATE
 #include "rusefi_wideband.h"
@@ -69,7 +68,7 @@ static char pin_error[64];
 
 static void benchOff(OutputPin* output) {
 #if EFI_PROD_CODE && (BOARD_EXT_GPIOCHIPS > 0)
-	brain_pin_diag_e diag = gpiochips_getDiag(output->brainPin);
+	brain_pin_diag_e diag = output->getDiag();
 	if (diag == PIN_INVALID) {
 		efiPrintf("No Diag on this pin");
 	} else {
diff --git a/firmware/controllers/sensors/sensor_checker.cpp b/firmware/controllers/sensors/sensor_checker.cpp
index 0ae52619c2..b32ac0df9c 100644
--- a/firmware/controllers/sensors/sensor_checker.cpp
+++ b/firmware/controllers/sensors/sensor_checker.cpp
@@ -121,6 +121,28 @@ static void check(SensorType type) {
 	}
 }
 
+static obd_code_e getCodeForInjector(int idx, brain_pin_diag_e diag) {
+	if (idx < 0 || idx >= 12) {
+		return OBD_None;
+	}
+
+	// TODO: do something more intelligent with `diag`?
+	UNUSED(diag);
+
+	return (obd_code_e)((int)OBD_Injector_Circuit_1 + idx);
+}
+
+static obd_code_e getCodeForIgnition(int idx, brain_pin_diag_e diag) {
+	if (idx < 0 || idx >= 12) {
+		return OBD_None;
+	}
+
+	// TODO: do something more intelligent with `diag`?
+	UNUSED(diag);
+
+	return (obd_code_e)((int)OBD_Ignition_Circuit_1 + idx);
+}
+
 void SensorChecker::onSlowCallback() {
 	// Don't check when the ignition is off, or when it was just turned on (let things stabilize)
 	// TODO: also inhibit checking if we just did a flash burn, since that blocks the ECU for a few seconds.
@@ -128,6 +150,7 @@ void SensorChecker::onSlowCallback() {
 		return;
 	}
 
+	// Check sensors
 	check(SensorType::Tps1Primary);
 	check(SensorType::Tps1Secondary);
 	check(SensorType::Tps1);
@@ -145,6 +168,47 @@ void SensorChecker::onSlowCallback() {
 	check(SensorType::Iat);
 
 	check(SensorType::FuelEthanolPercent);
+
+// only bother checking these if we have GPIO chips actually capable of reporting an error
+#if BOARD_EXT_GPIOCHIPS > 0 && EFI_PROD_CODE
+	// Check injectors
+	for (int i = 0; i < efi::size(enginePins.injectors); i++) {
+		InjectorOutputPin& pin = enginePins.injectors[i];
+
+		// Skip not-configured pins
+		if (!isBrainPinValid(pin.brainPin)) {
+			continue;
+		}
+
+		auto diag = pin.getDiag();
+		if (diag != PIN_OK) {
+			auto code = getCodeForInjector(i + 1, diag);
+
+			char description[32];
+			pinDiag2string(description, efi::size(description), diag);
+			warning(code, "Injector %d fault: %s", i, description);
+		}
+	}
+
+	// Check ignition
+	for (int i = 0; i < efi::size(enginePins.injectors); i++) {
+		IgnitionOutputPin& pin = enginePins.coils[i];
+
+		// Skip not-configured pins
+		if (!isBrainPinValid(pin.brainPin)) {
+			continue;
+		}
+
+		auto diag = pin.getDiag();
+		if (diag != PIN_OK) {
+			auto code = getCodeForIgnition(i + 1, diag);
+
+			char description[32];
+			pinDiag2string(description, efi::size(description), diag);
+			warning(code, "Ignition %d fault: %s", i, description);
+		}
+	}
+#endif // BOARD_EXT_GPIOCHIPS > 0
 }
 
 void SensorChecker::onIgnitionStateChanged(bool ignitionOn) {
diff --git a/firmware/controllers/sensors/sensor_checker.h b/firmware/controllers/sensors/sensor_checker.h
index d884a26f8c..1d93502658 100644
--- a/firmware/controllers/sensors/sensor_checker.h
+++ b/firmware/controllers/sensors/sensor_checker.h
@@ -1,5 +1,6 @@
 #pragma once
 
+// TODO: this name is now probably wrong, since it checks injectors/ignition too
 struct SensorChecker : public EngineModule {
 public:
 	void onSlowCallback() override;
diff --git a/firmware/controllers/system/efi_gpio.cpp b/firmware/controllers/system/efi_gpio.cpp
index 23ce194668..7488af0a51 100644
--- a/firmware/controllers/system/efi_gpio.cpp
+++ b/firmware/controllers/system/efi_gpio.cpp
@@ -475,6 +475,14 @@ void OutputPin::setDefaultPinState(const pin_output_mode_e *outputMode) {
 	setValue(false); // initial state
 }
 
+brain_pin_diag_e OutputPin::getDiag() const {
+#if BOARD_EXT_GPIOCHIPS > 0
+	return gpiochips_getDiag(brainPin);
+#else
+	return PIN_OK;
+#endif
+}
+
 void initOutputPins() {
 #if EFI_GPIO_HARDWARE
 
diff --git a/firmware/controllers/system/efi_gpio.h b/firmware/controllers/system/efi_gpio.h
index 3db75fe24d..3ceb0962a6 100644
--- a/firmware/controllers/system/efi_gpio.h
+++ b/firmware/controllers/system/efi_gpio.h
@@ -60,6 +60,8 @@ public:
 	void toggle();
 	bool getLogicValue() const;
 
+	brain_pin_diag_e getDiag() const;
+
 #if EFI_GPIO_HARDWARE
 	ioportid_t port = 0;
 	uint8_t pin = 0;