Update Configuration.h

Marlin/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active); 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/Cartesio/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/Felix/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Felix 2.0+ electronics with v4 Hotend

Marlin/example_configurations/Felix/DUAL/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Felix 2.0+ electronics with v4 Hotend

Marlin/example_configurations/Hephestos/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Hephestos i3

Marlin/example_configurations/Hephestos_2/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 250  // If the temperature difference between the target temperature and the actual temperature
-                                    // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Tuned PID values using M303

Marlin/example_configurations/K8200/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/K8400/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/K8400/Dual-head/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/RigidBot/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/SCARA/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 20 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Merlin Hotend: From Autotune

Marlin/example_configurations/TAZ4/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 70 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX 74 // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX 74 // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 16 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/WITBOX/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Witbox

Marlin/example_configurations/adafruit/ST7565/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/delta/biv2.5/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/delta/generic/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/delta/kossel_mini/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/delta/kossel_pro/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX  125 // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX  125 // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 50 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // Kossel Pro

Marlin/example_configurations/delta/kossel_xl/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/makibox/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it

Marlin/example_configurations/tvrrug/Round2/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active; 255=full current
 #if ENABLED(PIDTEMP)
   //#define PID_AUTOTUNE_MENU // Add PID Autotune to the LCD "Temperature" menu to run M303 and apply the result.
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
   //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                   // Set/get with gcode: M301 E[extruder number, 0-2]
-  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
-                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define K1 0.95 //smoothing factor within the PID
 
   // If you are using a pre-configured hotend then you can use one of the value sets by uncommenting it