diff --git a/firmware/controllers/algo/obd_error_codes.h b/firmware/controllers/algo/obd_error_codes.h
index e0f015b9f4..cc5fb0fb68 100644
--- a/firmware/controllers/algo/obd_error_codes.h
+++ b/firmware/controllers/algo/obd_error_codes.h
@@ -676,8 +676,8 @@ enum class ObdCode : uint16_t {
 	//P0639 Throttle Actuator Control Range/Performance (Bank 2)
 	//P0640 Intake Air Heater Control Circuit
 	//P0641 Sensor Reference Voltage “A” Circuit/Open
-	//P0642 Sensor Reference Voltage “A” Circuit Low
-	//P0643 Sensor Reference Voltage “A” Circuit High
+	Sensor5vSupplyLow = 642,
+	Sensor5vSupplyHigh = 643,
 	//P0644 Driver Display Serial Communication Circuit
 	//P0645 A/C Clutch Relay Control Circuit
 	//P0646 A/C Clutch Relay Control Circuit Low
diff --git a/firmware/controllers/sensors/sensor_checker.cpp b/firmware/controllers/sensors/sensor_checker.cpp
index 047d5d00ab..e52f9bf49a 100644
--- a/firmware/controllers/sensors/sensor_checker.cpp
+++ b/firmware/controllers/sensors/sensor_checker.cpp
@@ -147,17 +147,30 @@ static ObdCode getCodeForIgnition(int idx, brain_pin_diag_e diag) {
 #endif // BOARD_EXT_GPIOCHIPS > 0 && EFI_PROD_CODE
 
 void SensorChecker::onSlowCallback() {
-	bool batteryVoltageSufficient = Sensor::getOrZero(SensorType::BatteryVoltage) > 7.0f;
-
-	// Don't check when:
-	// - battery voltage is too low for sensors to work
-	// - the ignition is off
-	// - ignition was just turned on (let things stabilize first)
-	// TODO: also inhibit checking if we just did a flash burn, since that blocks the ECU for a few seconds.
-	bool shouldCheck = batteryVoltageSufficient && m_ignitionIsOn && m_timeSinceIgnOff.hasElapsedSec(5);
-	m_analogSensorsShouldWork = shouldCheck;
-	if (!shouldCheck) {
-		return;
+	if (Sensor::hasSensor(SensorType::Sensor5vVoltage)) {
+		float sensorSupply = Sensor::getOrZero(SensorType::Sensor5vVoltage);
+
+		// Inhibit checking if the sensor supply isn't OK, but register a warning for that instead
+		if (sensorSupply > 5.25f) {
+			warning(ObdCode::Sensor5vSupplyHigh, "5V sensor supply high: %.2f", sensorSupply);
+			return;
+		} else if (sensorSupply < 4.75f) {
+			warning(ObdCode::Sensor5vSupplyLow, "5V sensor supply low: %.2f", sensorSupply);
+			return;
+		}
+	} else {
+		bool batteryVoltageSufficient = Sensor::getOrZero(SensorType::BatteryVoltage) > 7.0f;
+
+		// Don't check when:
+		// - battery voltage is too low for sensors to work
+		// - the ignition is off
+		// - ignition was just turned on (let things stabilize first)
+		// TODO: also inhibit checking if we just did a flash burn, since that blocks the ECU for a few seconds.
+		bool shouldCheck = batteryVoltageSufficient && m_ignitionIsOn && m_timeSinceIgnOff.hasElapsedSec(5);
+		m_analogSensorsShouldWork = shouldCheck;
+		if (!shouldCheck) {
+			return;
+		}
 	}
 
 	// Check sensors
diff --git a/firmware/controllers/sensors/sensor_type.h b/firmware/controllers/sensors/sensor_type.h
index dae96d6497..c31c6932ee 100644
--- a/firmware/controllers/sensors/sensor_type.h
+++ b/firmware/controllers/sensors/sensor_type.h
@@ -71,6 +71,7 @@ enum class SensorType : unsigned char {
 
 	BatteryVoltage,
 	MainRelayVoltage,
+	Sensor5vVoltage,
 
 	BarometricPressure,