diff --git a/app/app.c b/app/app.c
index 2c704ac..4c0764b 100644
--- a/app/app.c
+++ b/app/app.c
@@ -209,19 +209,17 @@ void FUN_000051e8(void)
 		return;
 	}
 
-	bFlag = (gStepDirection == 0 || gCopyOfCodeType == CODE_TYPE_OFF);
+	bFlag = (gStepDirection == 0 && gCopyOfCodeType == CODE_TYPE_OFF);
 	if (gRxInfo->CHANNEL_SAVE >= NOAA_CHANNEL_FIRST && gSystickCountdown2) {
 		bFlag = true;
 		gSystickCountdown2 = 0;
 	}
 	if (g_CTCSS_Lost && gCopyOfCodeType == CODE_TYPE_CONTINUOUS_TONE) {
 		bFlag = true;
-		g_20000375 = 0;
+		gFoundCTCSS = false;
 	}
-	if (g_CDCSS_Lost && gCDCSSCodeReceived == 0x01) {
-		if (gCopyOfCodeType == CODE_TYPE_DIGITAL || gCopyOfCodeType == CODE_TYPE_REVERSE_DIGITAL) {
-			g_20000376 = 0;
-		}
+	if (g_CDCSS_Lost && gCDCSSCodeType == CDCSS_POSITIVE_CODE && (gCopyOfCodeType == CODE_TYPE_DIGITAL || gCopyOfCodeType == CODE_TYPE_REVERSE_DIGITAL)) {
+		gFoundCDCSS = false;
 	} else {
 		if (!bFlag) {
 			return;
@@ -295,10 +293,10 @@ void FUN_000052f0(void)
 
 	switch (gCopyOfCodeType) {
 	case CODE_TYPE_CONTINUOUS_TONE:
-		if (g_20000375 == 1) {
-			if (gSystickCountdown4 == 0) {
-				g_20000375 = 0;
-				g_20000376 = 0;
+		if (gFoundCTCSS) {
+			if (gFoundCTCSSCountdown == 0) {
+				gFoundCTCSS = false;
+				gFoundCDCSS = false;
 				Value = 1;
 				goto LAB_0000544c;
 			}
@@ -306,10 +304,10 @@ void FUN_000052f0(void)
 		break;
 	case CODE_TYPE_DIGITAL:
 	case CODE_TYPE_REVERSE_DIGITAL:
-		if (g_20000376 == 1) {
-			if (gSystickCountdown3 == 0) {
-				g_20000375 = 0;
-				g_20000376 = 0;
+		if (gFoundCDCSS) {
+			if (gFoundCDCSSCountdown == 0) {
+				gFoundCTCSS = false;
+				gFoundCDCSS = false;
 				Value = 1;
 				goto LAB_0000544c;
 			}
@@ -323,10 +321,10 @@ void FUN_000052f0(void)
 			switch (gCopyOfCodeType) {
 			case CODE_TYPE_CONTINUOUS_TONE:
 				if (g_CTCSS_Lost) {
-					g_20000375 = 0;
-				} else if (g_20000375 == 0) {
-					g_20000375 = 1;
-					gSystickCountdown4 = 100;
+					gFoundCTCSS = false;
+				} else if (!gFoundCTCSS) {
+					gFoundCTCSS = true;
+					gFoundCTCSSCountdown = 100;
 				}
 				if (g_CxCSS_TAIL_Found) {
 					Value = 2;
@@ -334,7 +332,7 @@ void FUN_000052f0(void)
 				}
 				break;
 			case CODE_TYPE_OFF:
-				if (gEeprom.SQUELCH_LEVEL != 0) {
+				if (gEeprom.SQUELCH_LEVEL) {
 					if (g_CxCSS_TAIL_Found) {
 						Value = 2;
 						g_CxCSS_TAIL_Found = false;
@@ -343,14 +341,14 @@ void FUN_000052f0(void)
 				break;
 			case CODE_TYPE_DIGITAL:
 			case CODE_TYPE_REVERSE_DIGITAL:
-				if (g_CDCSS_Lost && gCDCSSCodeReceived == 1) {
-					g_20000376 = 0;
-				} else if (g_20000376 == 0) {
-					g_20000376 = 1;
-					gSystickCountdown3 = 100;
+				if (g_CDCSS_Lost && gCDCSSCodeType == CDCSS_POSITIVE_CODE) {
+					gFoundCDCSS = false;
+				} else if (!gFoundCDCSS) {
+					gFoundCDCSS = true;
+					gFoundCDCSSCountdown = 100;
 				}
 				if (g_CxCSS_TAIL_Found) {
-					if (BK4819_GetCTCSSPhaseShift() == 1) {
+					if (BK4819_GetCTCType() == 1) {
 						Value = 2;
 					}
 					g_CxCSS_TAIL_Found = false;
@@ -368,7 +366,7 @@ void FUN_000052f0(void)
 		switch (gCopyOfCodeType) {
 		case CODE_TYPE_DIGITAL:
 		case CODE_TYPE_REVERSE_DIGITAL:
-			if (BK4819_GetCTCSSPhaseShift() == 1) {
+			if (BK4819_GetCTCType() == 1) {
 				gNextTimeslice40ms = false;
 			}
 			break;
@@ -377,9 +375,9 @@ void FUN_000052f0(void)
 		}
 	}
 
+LAB_0000544c:
 	gNextTimeslice40ms = false;
 
-LAB_0000544c:
 	switch (Value) {
 	case 1:
 		RADIO_SetupRegisters(true);
@@ -400,15 +398,13 @@ LAB_0000544c:
 		}
 		break;
 	case 2:
-		if (!gEeprom.TAIL_NOTE_ELIMINATION) {
-			gNextTimeslice40ms = false;
-			break;
+		if (gEeprom.TAIL_NOTE_ELIMINATION) {
+			GPIO_ClearBit(&GPIOC->DATA, GPIOC_PIN_AUDIO_PATH);
+			g_20000342 = 20;
+			gSystickFlag10 = false;
+			g_2000036B = 0;
+			g_20000377 = 1;
 		}
-		GPIO_ClearBit(&GPIOC->DATA, GPIOC_PIN_AUDIO_PATH);
-		g_20000342 = 20;
-		gSystickFlag10 = false;
-		g_2000036B = 0;
-		g_20000377 = 1;
 		break;
 	default:
 		break;
@@ -693,7 +689,7 @@ void APP_CheckRadioInterrupts(void)
 		}
 		if (Mask & BK4819_REG_02_CDCSS_LOST) {
 			g_CDCSS_Lost = true;
-			gCDCSSCodeReceived = BK4819_CheckCDCSSCodeReceived();
+			gCDCSSCodeType = BK4819_GetCDCSSCodeType();
 		}
 		if (Mask & BK4819_REG_02_CDCSS_FOUND) {
 			g_CDCSS_Lost = false;
@@ -1431,7 +1427,7 @@ void FUN_000075b0(void)
 	g_200003AA = 0;
 	g_CxCSS_TAIL_Found = false;
 	g_CDCSS_Lost = false;
-	gCDCSSCodeReceived = 0;
+	gCDCSSCodeType = 0;
 	g_CTCSS_Lost = false;
 	g_VOX_Lost = false;
 	g_SquelchLost = false;
diff --git a/dcs.h b/dcs.h
index 122b457..26702de 100644
--- a/dcs.h
+++ b/dcs.h
@@ -28,6 +28,11 @@ enum DCS_CodeType_t {
 
 typedef enum DCS_CodeType_t DCS_CodeType_t;
 
+enum {
+	CDCSS_POSITIVE_CODE = 1U,
+	CDCSS_NEGATIVE_CODE = 2U,
+};
+
 extern const uint16_t CTCSS_Options[50];
 extern const uint16_t DCS_Options[104];
 
diff --git a/driver/bk4819.c b/driver/bk4819.c
index fbb7503..ad78fe5 100644
--- a/driver/bk4819.c
+++ b/driver/bk4819.c
@@ -814,14 +814,14 @@ uint8_t BK4819_GetDTMF_5TONE_Code(void)
         return (BK4819_GetRegister(BK4819_REG_0B) >> 8) & 0x0F;
 }
 
-uint8_t BK4819_CheckCDCSSCodeReceived(void)
+uint8_t BK4819_GetCDCSSCodeType(void)
 {
         return (BK4819_GetRegister(BK4819_REG_0C) >> 14) & 3;
 }
 
-uint8_t BK4819_GetCTCSSPhaseShift(void)
+uint8_t BK4819_GetCTCType(void)
 {
-        return (BK4819_GetRegister(BK4819_REG_0C) >> 14) & 3;
+        return (BK4819_GetRegister(BK4819_REG_0C) >> 10) & 3;
 }
 
 void BK4819_SendFSKData(uint16_t *pData)
diff --git a/driver/bk4819.h b/driver/bk4819.h
index 69a0c31..28f201c 100644
--- a/driver/bk4819.h
+++ b/driver/bk4819.h
@@ -122,8 +122,8 @@ void BK4819_StopScan(void);
 
 uint8_t BK4819_GetDTMF_5TONE_Code(void);
 
-uint8_t BK4819_CheckCDCSSCodeReceived(void);
-uint8_t BK4819_GetCTCSSPhaseShift(void);
+uint8_t BK4819_GetCDCSSCodeType(void);
+uint8_t BK4819_GetCTCType(void);
 
 void BK4819_SendFSKData(uint16_t *pData);
 void BK4819_PrepareFSKReceive(void);
diff --git a/functions.c b/functions.c
index 774df1b..4e87535 100644
--- a/functions.c
+++ b/functions.c
@@ -58,10 +58,10 @@ void FUNCTION_Init(void)
 	g_SquelchLost = false;
 	g_20000342 = 0;
 	gSystickFlag10 = false;
-	g_20000375 = 0;
-	g_20000376 = 0;
-	gSystickCountdown4 = 0;
-	gSystickCountdown3 = 0;
+	gFoundCTCSS = false;
+	gFoundCDCSS = false;
+	gFoundCTCSSCountdown = 0;
+	gFoundCDCSSCountdown = 0;
 	g_20000377 = 0;
 	gSystickCountdown2 = 0;
 }
diff --git a/misc.c b/misc.c
index 468fce1..053cb07 100644
--- a/misc.c
+++ b/misc.c
@@ -61,8 +61,8 @@ uint8_t gUpdateStatus;
 uint8_t g_20000370;
 uint8_t g_20000371[2];
 uint8_t g_20000373;
-uint8_t g_20000375;
-uint8_t g_20000376;
+uint8_t gFoundCTCSS;
+uint8_t gFoundCDCSS;
 uint8_t g_20000377;
 uint8_t gVFO_RSSI_Level[2];
 uint8_t g_2000037E;
@@ -96,7 +96,7 @@ uint8_t gFlagSaveChannel;
 bool gFlagSaveFM;
 uint8_t g_200003AA;
 bool g_CDCSS_Lost;
-uint8_t gCDCSSCodeReceived;
+uint8_t gCDCSSCodeType;
 bool g_CTCSS_Lost;
 bool g_CxCSS_TAIL_Found;
 bool g_VOX_Lost;
@@ -173,8 +173,8 @@ uint8_t gScanPauseMode;
 uint8_t gScanState;
 uint8_t gShowChPrefix;
 volatile uint16_t gSystickCountdown2;
-volatile uint8_t gSystickCountdown3;
-volatile uint8_t gSystickCountdown4;
+volatile uint8_t gFoundCDCSSCountdown;
+volatile uint8_t gFoundCTCSSCountdown;
 volatile uint16_t gSystickCountdown11;
 volatile bool gTxTimeoutReached;
 volatile bool gNextTimeslice40ms;
diff --git a/misc.h b/misc.h
index c3d95f1..cca5abf 100644
--- a/misc.h
+++ b/misc.h
@@ -85,8 +85,8 @@ extern uint8_t gUpdateStatus;
 extern uint8_t g_20000370;
 extern uint8_t g_20000371[2];
 extern uint8_t g_20000373;
-extern uint8_t g_20000375;
-extern uint8_t g_20000376;
+extern uint8_t gFoundCTCSS;
+extern uint8_t gFoundCDCSS;
 extern uint8_t g_20000377;
 extern uint8_t gVFO_RSSI_Level[2];
 extern uint8_t g_2000037E;
@@ -120,7 +120,7 @@ extern uint8_t gFlagSaveChannel;
 extern bool gFlagSaveFM;
 extern uint8_t g_200003AA;
 extern bool g_CDCSS_Lost;
-extern uint8_t gCDCSSCodeReceived;
+extern uint8_t gCDCSSCodeType;
 extern bool g_CTCSS_Lost;
 extern bool g_CxCSS_TAIL_Found;
 extern bool g_VOX_Lost;
@@ -197,8 +197,8 @@ extern uint8_t gScanPauseMode;
 extern uint8_t gScanState;
 extern uint8_t gShowChPrefix;
 extern volatile uint16_t gSystickCountdown2;
-extern volatile uint8_t gSystickCountdown3;
-extern volatile uint8_t gSystickCountdown4;
+extern volatile uint8_t gFoundCDCSSCountdown;
+extern volatile uint8_t gFoundCTCSSCountdown;
 extern volatile uint16_t gSystickCountdown11;
 extern volatile bool gTxTimeoutReached;
 extern volatile bool gNextTimeslice40ms;
diff --git a/scheduler.c b/scheduler.c
index 587700d..42e9eb6 100644
--- a/scheduler.c
+++ b/scheduler.c
@@ -43,11 +43,11 @@ void SystickHandler(void)
 	if (gSystickCountdown2) {
 		gSystickCountdown2--;
 	}
-	if (gSystickCountdown3) {
-		gSystickCountdown3--;
+	if (gFoundCDCSSCountdown) {
+		gFoundCDCSSCountdown--;
 	}
-	if (gSystickCountdown4) {
-		gSystickCountdown4--;
+	if (gFoundCTCSSCountdown) {
+		gFoundCTCSSCountdown--;
 	}
 	if (gCurrentFunction == FUNCTION_0 && gBatterySaveCountdown) {
 		gBatterySaveCountdown--;