diff --git a/firmware/controllers/algo/obd_error_codes.h b/firmware/controllers/algo/obd_error_codes.h
index 14f126c0ef..34c2377fcf 100644
--- a/firmware/controllers/algo/obd_error_codes.h
+++ b/firmware/controllers/algo/obd_error_codes.h
@@ -687,7 +687,7 @@ enum class ObdCode : uint16_t {
 	OBD_Throttle_Actuator_Control_Range_Performance_Bank_1 = 638,
 	//P0639 Throttle Actuator Control Range/Performance (Bank 2)
 	//P0640 Intake Air Heater Control Circuit
-	//P0641 Sensor Reference Voltage “A” Circuit/Open
+	OBD_Sensor_Refence_Voltate_A_Open = 641,
 	//P0642 Sensor Reference Voltage “A” Circuit Low
 	//P0643 Sensor Reference Voltage “A” Circuit High
 	//P0644 Driver Display Serial Communication Circuit
diff --git a/firmware/controllers/sensors/sensor_checker.cpp b/firmware/controllers/sensors/sensor_checker.cpp
index e6331ab9d0..f0a60d3c45 100644
--- a/firmware/controllers/sensors/sensor_checker.cpp
+++ b/firmware/controllers/sensors/sensor_checker.cpp
@@ -197,8 +197,9 @@ void SensorChecker::onSlowCallback() {
 
 	check(SensorType::FuelEthanolPercent);
 
+#if EFI_PROD_CODE
 // only bother checking these if we have GPIO chips actually capable of reporting an error
-#if BOARD_EXT_GPIOCHIPS > 0 && EFI_PROD_CODE
+#if BOARD_EXT_GPIOCHIPS > 0
 	TunerStudioOutputChannels *state = getTunerStudioOutputChannels();
 	// Check injectors
 #if EFI_ENGINE_CONTROL
@@ -248,6 +249,14 @@ void SensorChecker::onSlowCallback() {
 		state->ignitorDiagnostic[i] = getTSErrorCode(diag);
 	}
 #endif // BOARD_EXT_GPIOCHIPS > 0
+
+	// Check ADC(s) and analog inputs
+	if (analogGetDiagnostic() < 0) {
+		/* TODO: map to more OBD codes? */
+		warning(ObdCode::OBD_Sensor_Refence_Voltate_A_Open, "Analog subsystem fault");
+	}
+#endif // EFI_PROD_CODE
+
   boardSensorChecker();
 }
 
diff --git a/firmware/hw_layer/adc/adc_inputs.cpp b/firmware/hw_layer/adc/adc_inputs.cpp
index 5ec61c66ed..f2268aaaeb 100644
--- a/firmware/hw_layer/adc/adc_inputs.cpp
+++ b/firmware/hw_layer/adc/adc_inputs.cpp
@@ -32,6 +32,13 @@ int PUBLIC_API_WEAK boardGetAnalogInputDiagnostic(adc_channel_e channel, float)
 	return 0;
 }
 
+/* Get analog part diagnostic */
+int analogGetDiagnostic()
+{
+	/* TODO: debounce? */
+	return boardGetAnalogDiagnostic();
+}
+
 #if HAL_USE_ADC
 
 #include "adc_subscription.h"
diff --git a/firmware/hw_layer/adc/adc_inputs.h b/firmware/hw_layer/adc/adc_inputs.h
index 4fd83f7560..c076554c1c 100644
--- a/firmware/hw_layer/adc/adc_inputs.h
+++ b/firmware/hw_layer/adc/adc_inputs.h
@@ -38,6 +38,7 @@ inline bool isAdcChannelOffChip(adc_channel_e hwChannel) {
 	return (isAdcChannelValid(hwChannel) && (hwChannel > EFI_ADC_ONCHIP_LAST));
 }
 
+int analogGetDiagnostic();
 
 #if !defined(GPT_FREQ_FAST) || !defined(GPT_PERIOD_FAST)