diff --git a/firmware/hw_layer/adc/AdcConfiguration.h b/firmware/hw_layer/adc/AdcConfiguration.h
index d3dbba01f5..96911d28d5 100644
--- a/firmware/hw_layer/adc/AdcConfiguration.h
+++ b/firmware/hw_layer/adc/AdcConfiguration.h
@@ -24,8 +24,7 @@ public:
 	void enableChannel(adc_channel_e hwChannelIndex);
 	void enableChannelAndPin(const char *msg, adc_channel_e hwChannelIndex);
 	adc_channel_e getAdcHardwareIndexByInternalIndex(int index) const;
-	/* We use adc_channel_e as index for following array */
-	char internalAdcIndexByHardwareIndex[EFI_ADC_LAST + 1];
+	int internalAdcIndexByHardwareIndex[ADC_MAX_CHANNELS_COUNT + 4];
 	bool isHwUsed(adc_channel_e hwChannel) const;
 	int size() const;
 	void init(void);
@@ -39,14 +38,13 @@ public:
 	int getAdcValueByHwChannel(adc_channel_e hwChannel) const;
 
 	adc_state values;
+	int channelCount;
 private:
 	ADCConversionGroup* hwConfig;
 	/**
 	 * Number of ADC channels in use
 	 */
-	unsigned char channelCount;
-
-	/* STM32 has up-to 4 additional channels routed to internal voltage sources */
+	 
 	adc_channel_e hardwareIndexByIndernalAdcIndex[ADC_MAX_CHANNELS_COUNT + 4];
 };
 
diff --git a/firmware/hw_layer/adc/adc_inputs.cpp b/firmware/hw_layer/adc/adc_inputs.cpp
index 6b9ce1a8b4..6e4965d5c1 100644
--- a/firmware/hw_layer/adc/adc_inputs.cpp
+++ b/firmware/hw_layer/adc/adc_inputs.cpp
@@ -76,7 +76,7 @@ AdcDevice::AdcDevice(ADCConversionGroup* hwConfig, adcsample_t *buf) {
 	hwConfig->sqr5 = 0;
 #endif /* ADC_MAX_CHANNELS_COUNT */
 	memset(hardwareIndexByIndernalAdcIndex, EFI_ADC_NONE, sizeof(hardwareIndexByIndernalAdcIndex));
-	memset(internalAdcIndexByHardwareIndex, EFI_ADC_ERROR, sizeof(internalAdcIndexByHardwareIndex));
+	memset(internalAdcIndexByHardwareIndex, 0xFFFFFFFF, sizeof(internalAdcIndexByHardwareIndex));
 }
 
 #if !defined(GPT_FREQ_FAST) || !defined(GPT_PERIOD_FAST)
@@ -315,21 +315,13 @@ int AdcDevice::size() const {
 	return channelCount;
 }
 
-int AdcDevice::getAdcValueByIndex(int internalIndex) const {
-	if (internalIndex >= size()) {
-		firmwareError(OBD_PCM_Processor_Fault, "ADC channel index out of range %d", internalIndex);
-		return 0;
-	}
+int AdcDevice::getAdcValueByHwChannel(adc_channel_e hwChannel) const {
+	int internalIndex = internalAdcIndexByHardwareIndex[hwChannel];
 	return values.adc_data[internalIndex];
 }
 
-int AdcDevice::getAdcValueByHwChannel(adc_channel_e hwChannel) const {
-	if (hwChannel >= ARRAY_SIZE(internalAdcIndexByHardwareIndex)) {
-		firmwareError(OBD_PCM_Processor_Fault, "ADC hwChannel out of range");
-		return 0;
-	}
-	int internalIndex = internalAdcIndexByHardwareIndex[hwChannel];
-	return getAdcValueByIndex(internalIndex);
+int AdcDevice::getAdcValueByIndex(int internalIndex) const {
+	return values.adc_data[internalIndex];
 }
 
 void AdcDevice::invalidateSamplesCache() {
@@ -359,7 +351,7 @@ bool AdcDevice::isHwUsed(adc_channel_e hwChannelIndex) const {
 }
 
 void AdcDevice::enableChannel(adc_channel_e hwChannel) {
-	if (channelCount >= ADC_MAX_CHANNELS_COUNT) {
+	if (channelCount >= efi::size(values.adc_data)) {
 		firmwareError(OBD_PCM_Processor_Fault, "Too many ADC channels configured");
 		return;
 	}