diff --git a/sonoff/settings.h b/sonoff/settings.h
index 83a26e311..22f6d940d 100644
--- a/sonoff/settings.h
+++ b/sonoff/settings.h
@@ -163,6 +163,20 @@ typedef union {
   };
 } Mcp230xxCfg;
 
+typedef union {
+  uint8_t data;
+  struct {
+    uint8_t spare0 : 1;
+    uint8_t spare1 : 1;
+    uint8_t spare2 : 1;
+    uint8_t spare3 : 1;
+    uint8_t spare4 : 1;
+    uint8_t spare5 : 1;
+    uint8_t spare6 : 1;
+    uint8_t mhz19b_abc_disable : 1;        // Disable ABC (Automatic Baseline Correction for MHZ19(B) (0 = Enabled (default), 1 = Disabled with Sensor15 command)
+  };
+} SensorCfg1;
+    
 /*
 struct SYSCFG {
   unsigned long cfg_holder;                // 000 Pre v6 header
@@ -311,8 +325,7 @@ struct SYSCFG {
   uint8_t       knx_CB_param[MAX_KNX_CB];  // 6EC  Type of Output (set relay, toggle relay, reply sensor value)
   Mcp230xxCfg   mcp230xx_config[16];       // 6F6
   uint8_t       mcp230xx_int_prio;         // 716
-
-  uint8_t       free_717[1];               // 717
+  SensorCfg1    SensorBits1;               // 717  On/Off settings used by Sensor Commands
 
   uint16_t      mcp230xx_int_timer;        // 718
   uint8_t       rgbwwTable[5];             // 71A
diff --git a/sonoff/xsns_15_mhz19.ino b/sonoff/xsns_15_mhz19.ino
index 509f9e0bc..747a8125f 100644
--- a/sonoff/xsns_15_mhz19.ino
+++ b/sonoff/xsns_15_mhz19.ino
@@ -39,7 +39,10 @@ enum MhzFilterOptions {MHZ19_FILTER_OFF, MHZ19_FILTER_OFF_ALLSAMPLES, MHZ19_FILT
 /*********************************************************************************************\
  * Source: http://www.winsen-sensor.com/d/files/infrared-gas-sensor/mh-z19b-co2-ver1_0.pdf
  *
- * Automatic Baseline Correction (ABC logic function)
+ * Automatic Baseline Correction (ABC logic function) is enabled by default but may be disabled with command
+ * Sensor15 0
+ * and enabled again with command
+ * Sensor15 1
  *
  * ABC logic function refers to that sensor itself do zero point judgment and automatic calibration procedure
  * intelligently after a continuous operation period. The automatic calibration cycle is every 24 hours after powered on.
@@ -52,10 +55,6 @@ enum MhzFilterOptions {MHZ19_FILTER_OFF, MHZ19_FILTER_OFF_ALLSAMPLES, MHZ19_FILT
  * Please do zero calibration timely, such as manual or commend calibration.
 \*********************************************************************************************/
 
-#define MHZ19_ABC_ENABLE             1       // Automatic Baseline Correction (0 = off, 1 = on (default))
-
-/*********************************************************************************************/
-
 #include <TasmotaSerial.h>
 
 #ifndef CO2_LOW
@@ -72,6 +71,9 @@ TasmotaSerial *MhzSerial;
 
 const char kMhzModels[] PROGMEM = "|B";
 
+const char ABC_ENABLED[] PROGMEM = "ABC is Enabled";
+const char ABC_DISABLED[] PROGMEM = "ABC is Enabled";
+
 enum MhzCommands { MHZ_CMND_READPPM, MHZ_CMND_ABCENABLE, MHZ_CMND_ABCDISABLE, MHZ_CMND_ZEROPOINT, MHZ_CMND_RESET, MHZ_CMND_RANGE_1000, MHZ_CMND_RANGE_2000, MHZ_CMND_RANGE_3000, MHZ_CMND_RANGE_5000 };
 const uint8_t kMhzCommands[][4] PROGMEM = {
 //  2     3    6    7
@@ -88,7 +90,6 @@ const uint8_t kMhzCommands[][4] PROGMEM = {
 uint8_t mhz_type = 1;
 uint16_t mhz_last_ppm = 0;
 uint8_t mhz_filter = MHZ19_FILTER_OPTION;
-bool mhz_abc_enable = MHZ19_ABC_ENABLE;
 bool mhz_abc_must_apply = false;
 
 float mhz_temperature = 0;
@@ -218,7 +219,7 @@ void MhzEverySecond(void)
 
     uint16_t u = (mhz_response[6] << 8) | mhz_response[7];
     if (15000 == u) {      // During (and only ever at) sensor boot, 'u' is reported as 15000
-      if (!mhz_abc_enable) {
+      if (Settings.SensorBits1.mhz19b_abc_disable) {
         // After bootup of the sensor the ABC will be enabled.
         // Thus only actively disable after bootup.
         mhz_abc_must_apply = true;
@@ -235,7 +236,7 @@ void MhzEverySecond(void)
         if (0 == s || 64 == s) {  // Reading is stable.
           if (mhz_abc_must_apply) {
             mhz_abc_must_apply = false;
-            if (mhz_abc_enable) {
+            if (!Settings.SensorBits1.mhz19b_abc_disable) {
               MhzSendCmd(MHZ_CMND_ABCENABLE);
             } else {
               MhzSendCmd(MHZ_CMND_ABCDISABLE);
@@ -252,8 +253,8 @@ void MhzEverySecond(void)
 /*********************************************************************************************\
  * Command Sensor15
  *
- * 0    - (Not implemented) ABC Off
- * 1    - (Not implemented) ABC On
+ * 0    - ABC Off
+ * 1    - ABC On (Default)
  * 2    - Manual start = ABC Off
  * 3    - (Not implemented) Optional filter settings
  * 9    - Reset
@@ -273,6 +274,16 @@ bool MhzCommandSensor(void)
   bool serviced = true;
 
   switch (XdrvMailbox.payload) {
+    case 0:
+      Settings.SensorBits1.mhz19b_abc_disable = true;
+      MhzSendCmd(MHZ_CMND_ABCDISABLE);
+      snprintf_P(mqtt_data, sizeof(mqtt_data), S_JSON_SENSOR_INDEX_SVALUE, XSNS_15, ABC_DISABLED);
+      break;
+    case 1:
+      Settings.SensorBits1.mhz19b_abc_disable = false;
+      MhzSendCmd(MHZ_CMND_ABCENABLE);
+      snprintf_P(mqtt_data, sizeof(mqtt_data), S_JSON_SENSOR_INDEX_SVALUE, XSNS_15, ABC_ENABLED);
+      break;
     case 2:
       MhzSendCmd(MHZ_CMND_ZEROPOINT);
       snprintf_P(mqtt_data, sizeof(mqtt_data), S_JSON_SENSOR_INDEX_SVALUE, XSNS_15, D_JSON_ZERO_POINT_CALIBRATION);
@@ -298,7 +309,11 @@ bool MhzCommandSensor(void)
       snprintf_P(mqtt_data, sizeof(mqtt_data), S_JSON_SENSOR_INDEX_SVALUE, XSNS_15, D_JSON_RANGE_5000);
       break;
     default:
-      serviced = false;
+      if (!Settings.SensorBits1.mhz19b_abc_disable) {
+        snprintf_P(mqtt_data, sizeof(mqtt_data), S_JSON_SENSOR_INDEX_SVALUE, XSNS_15, ABC_ENABLED);
+      } else {
+        snprintf_P(mqtt_data, sizeof(mqtt_data), S_JSON_SENSOR_INDEX_SVALUE, XSNS_15, ABC_DISABLED);
+      }
   }
 
   return serviced;