diff --git a/Marlin/src/Marlin.cpp b/Marlin/src/Marlin.cpp
index e089e034c..a13d7f19a 100644
--- a/Marlin/src/Marlin.cpp
+++ b/Marlin/src/Marlin.cpp
@@ -264,6 +264,11 @@ bool pin_is_protected(const pin_t pin) {
   return false;
 }
 
+void protected_pin_err() {
+  SERIAL_ERROR_START();
+  SERIAL_ERRORLNPGM(MSG_ERR_PROTECTED_PIN);
+}
+
 void quickstop_stepper() {
   planner.quick_stop();
   planner.synchronize();
diff --git a/Marlin/src/Marlin.h b/Marlin/src/Marlin.h
index cda7d0a7b..6dae6b5d5 100644
--- a/Marlin/src/Marlin.h
+++ b/Marlin/src/Marlin.h
@@ -219,6 +219,7 @@ extern millis_t max_inactive_time, stepper_inactive_time;
 #endif
 
 bool pin_is_protected(const pin_t pin);
+void protected_pin_err();
 
 #if HAS_SUICIDE
   inline void suicide() { OUT_WRITE(SUICIDE_PIN, LOW); }
diff --git a/Marlin/src/gcode/config/M43.cpp b/Marlin/src/gcode/config/M43.cpp
index c00046802..e9d36efd6 100644
--- a/Marlin/src/gcode/config/M43.cpp
+++ b/Marlin/src/gcode/config/M43.cpp
@@ -35,7 +35,7 @@
 #endif
 
 inline void toggle_pins() {
-  const bool I_flag = parser.boolval('I');
+  const bool ignore_protection = parser.boolval('I');
   const int repeat = parser.intval('R', 1),
             start = PARSED_PIN_INDEX('S', 0),
             end = PARSED_PIN_INDEX('E', NUM_DIGITAL_PINS - 1),
@@ -43,14 +43,14 @@ inline void toggle_pins() {
 
   for (uint8_t i = start; i <= end; i++) {
     pin_t pin = GET_PIN_MAP_PIN(i);
-    //report_pin_state_extended(pin, I_flag, false);
+    //report_pin_state_extended(pin, ignore_protection, false);
     if (!VALID_PIN(pin)) continue;
-    if (!I_flag && pin_is_protected(pin)) {
-      report_pin_state_extended(pin, I_flag, true, "Untouched ");
+    if (!ignore_protection && pin_is_protected(pin)) {
+      report_pin_state_extended(pin, ignore_protection, true, "Untouched ");
       SERIAL_EOL();
     }
     else {
-      report_pin_state_extended(pin, I_flag, true, "Pulsing   ");
+      report_pin_state_extended(pin, ignore_protection, true, "Pulsing   ");
       #if AVR_AT90USB1286_FAMILY // Teensy IDEs don't know about these pins so must use FASTIO
         if (pin == TEENSY_E2) {
           SET_OUTPUT(TEENSY_E2);
@@ -275,7 +275,7 @@ void GcodeSuite::M43() {
     for (uint8_t i = first_pin; i <= last_pin; i++) {
       pin_t pin = GET_PIN_MAP_PIN(i);
       if (!VALID_PIN(pin)) continue;
-      if (pin_is_protected(pin) && !ignore_protection) continue;
+      if (!ignore_protection && pin_is_protected(pin)) continue;
       pinMode(pin, INPUT_PULLUP);
       delay(1);
       /*
@@ -295,7 +295,7 @@ void GcodeSuite::M43() {
       for (uint8_t i = first_pin; i <= last_pin; i++) {
         pin_t pin = GET_PIN_MAP_PIN(i);
         if (!VALID_PIN(pin)) continue;
-        if (pin_is_protected(pin) && !ignore_protection) continue;
+        if (!ignore_protection && pin_is_protected(pin)) continue;
         const byte val =
           /*
             IS_ANALOG(pin)
diff --git a/Marlin/src/gcode/control/M226.cpp b/Marlin/src/gcode/control/M226.cpp
index 51ee96b9b..59071aadf 100644
--- a/Marlin/src/gcode/control/M226.cpp
+++ b/Marlin/src/gcode/control/M226.cpp
@@ -33,27 +33,20 @@ void GcodeSuite::M226() {
               pin_state = parser.intval('S', -1); // required pin state - default is inverted
     const pin_t pin = GET_PIN_MAP_PIN(pin_number);
 
-    if (WITHIN(pin_state, -1, 1) && pin > -1 && !pin_is_protected(pin)) {
-
-      int target = LOW;
-
-      planner.synchronize();
-
-      pinMode(pin, INPUT);
-      switch (pin_state) {
-        case 1:
-          target = HIGH;
-          break;
-        case 0:
-          target = LOW;
-          break;
-        case -1:
-          target = !digitalRead(pin);
-          break;
+    if (WITHIN(pin_state, -1, 1) && pin > -1) {
+      if (pin_is_protected(pin))
+        protected_pin_err();
+      else {
+        int target = LOW;
+        planner.synchronize();
+        pinMode(pin, INPUT);
+        switch (pin_state) {
+          case 1: target = HIGH; break;
+          case 0: target = LOW; break;
+          case -1: target = !digitalRead(pin); break;
+        }
+        while (digitalRead(pin) != target) idle();
       }
-
-      while (digitalRead(pin) != target) idle();
-
     } // pin_state -1 0 1 && pin > -1
   } // parser.seen('P')
 }
diff --git a/Marlin/src/gcode/control/M42.cpp b/Marlin/src/gcode/control/M42.cpp
index 5b0a53682..4dd27b1da 100644
--- a/Marlin/src/gcode/control/M42.cpp
+++ b/Marlin/src/gcode/control/M42.cpp
@@ -41,11 +41,8 @@ void GcodeSuite::M42() {
   if (pin_index < 0) return;
 
   const pin_t pin = GET_PIN_MAP_PIN(pin_index);
-  if (pin_is_protected(pin)) {
-    SERIAL_ERROR_START();
-    SERIAL_ERRORLNPGM(MSG_ERR_PROTECTED_PIN);
-    return;
-  }
+
+  if (pin_is_protected(pin_number)) return protected_pin_err();
 
   pinMode(pin, OUTPUT);
   digitalWrite(pin, pin_status);