diff --git a/Marlin/Conditionals_post.h b/Marlin/Conditionals_post.h
index de2e6e2af9..6e0f10f1c4 100644
--- a/Marlin/Conditionals_post.h
+++ b/Marlin/Conditionals_post.h
@@ -440,10 +440,16 @@
   #define HAS_AUTO_FAN_1 (PIN_EXISTS(EXTRUDER_1_AUTO_FAN))
   #define HAS_AUTO_FAN_2 (PIN_EXISTS(EXTRUDER_2_AUTO_FAN))
   #define HAS_AUTO_FAN_3 (PIN_EXISTS(EXTRUDER_3_AUTO_FAN))
+  #define AUTO_1_IS_0 (EXTRUDER_1_AUTO_FAN_PIN == EXTRUDER_0_AUTO_FAN_PIN)
+  #define AUTO_2_IS_0 (EXTRUDER_2_AUTO_FAN_PIN == EXTRUDER_0_AUTO_FAN_PIN)
+  #define AUTO_2_IS_1 (EXTRUDER_2_AUTO_FAN_PIN == EXTRUDER_1_AUTO_FAN_PIN)
+  #define AUTO_3_IS_0 (EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_0_AUTO_FAN_PIN)
+  #define AUTO_3_IS_1 (EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_1_AUTO_FAN_PIN)
+  #define AUTO_3_IS_2 (EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_2_AUTO_FAN_PIN)
   #define HAS_AUTO_FAN (HAS_AUTO_FAN_0 || HAS_AUTO_FAN_1 || HAS_AUTO_FAN_2 || HAS_AUTO_FAN_3)
   #define HAS_FAN0 (PIN_EXISTS(FAN))
-  #define HAS_FAN1 (PIN_EXISTS(FAN1) && CONTROLLERFAN_PIN != FAN1_PIN && EXTRUDER_0_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_1_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_2_AUTO_FAN_PIN != FAN1_PIN)
-  #define HAS_FAN2 (PIN_EXISTS(FAN2) && CONTROLLERFAN_PIN != FAN2_PIN && EXTRUDER_0_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_1_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_2_AUTO_FAN_PIN != FAN2_PIN)
+  #define HAS_FAN1 (PIN_EXISTS(FAN1) && CONTROLLERFAN_PIN != FAN1_PIN && EXTRUDER_0_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_1_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_2_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_3_AUTO_FAN_PIN != FAN1_PIN)
+  #define HAS_FAN2 (PIN_EXISTS(FAN2) && CONTROLLERFAN_PIN != FAN2_PIN && EXTRUDER_0_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_1_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_2_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_3_AUTO_FAN_PIN != FAN2_PIN)
   #define HAS_CONTROLLERFAN (PIN_EXISTS(CONTROLLERFAN))
   #define HAS_SERVOS (defined(NUM_SERVOS) && NUM_SERVOS > 0)
   #define HAS_SERVO_0 (PIN_EXISTS(SERVO0))
diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 4cb3ed98ca..78168c2e96 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -185,7 +185,7 @@ int Temperature::minttemp_raw[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_RAW_LO_TEMP ,
 #endif
 
 #if HAS_AUTO_FAN
-  millis_t Temperature::next_auto_fan_check_ms;
+  millis_t Temperature::next_auto_fan_check_ms = 0;
 #endif
 
 unsigned char Temperature::soft_pwm[HOTENDS];
@@ -465,21 +465,21 @@ int Temperature::getHeaterPower(int heater) {
 
   void Temperature::checkExtruderAutoFans() {
     const int8_t fanPin[] = { EXTRUDER_0_AUTO_FAN_PIN, EXTRUDER_1_AUTO_FAN_PIN, EXTRUDER_2_AUTO_FAN_PIN, EXTRUDER_3_AUTO_FAN_PIN };
-    const int fanBit[] = { 0,
-      EXTRUDER_1_AUTO_FAN_PIN == EXTRUDER_0_AUTO_FAN_PIN ? 0 : 1,
-      EXTRUDER_2_AUTO_FAN_PIN == EXTRUDER_0_AUTO_FAN_PIN ? 0 :
-      EXTRUDER_2_AUTO_FAN_PIN == EXTRUDER_1_AUTO_FAN_PIN ? 1 : 2,
-      EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_0_AUTO_FAN_PIN ? 0 :
-      EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_1_AUTO_FAN_PIN ? 1 :
-      EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_2_AUTO_FAN_PIN ? 2 : 3
+    const int fanBit[] = {
+                    0,
+      AUTO_1_IS_0 ? 0 :               1,
+      AUTO_2_IS_0 ? 0 : AUTO_2_IS_1 ? 1 :               2,
+      AUTO_3_IS_0 ? 0 : AUTO_3_IS_1 ? 1 : AUTO_3_IS_2 ? 2 : 3
     };
     uint8_t fanState = 0;
+ 
     HOTEND_LOOP() {
       if (current_temperature[e] > EXTRUDER_AUTO_FAN_TEMPERATURE)
         SBI(fanState, fanBit[e]);
     }
+ 
     uint8_t fanDone = 0;
-    for (int8_t f = 0; f <= 3; f++) {
+    for (int8_t f = 0; f < COUNT(fanPin); f++) {
       int8_t pin = fanPin[f];
       if (pin >= 0 && !TEST(fanDone, fanBit[f])) {
         unsigned char newFanSpeed = TEST(fanState, fanBit[f]) ? EXTRUDER_AUTO_FAN_SPEED : 0;
@@ -987,39 +987,35 @@ void Temperature::init() {
     SET_OUTPUT(HEATER_BED_PIN);
   #endif
 
-  #if ENABLED(FAST_PWM_FAN) || ENABLED(FAN_SOFT_PWM)
-
-    #if HAS_FAN0
-      SET_OUTPUT(FAN_PIN);
-      #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
-      #endif
-      #if ENABLED(FAN_SOFT_PWM)
-        soft_pwm_fan[0] = fanSpeedSoftPwm[0] / 2;
-      #endif
+  #if HAS_FAN0
+    SET_OUTPUT(FAN_PIN);
+    #if ENABLED(FAST_PWM_FAN)
+      setPwmFrequency(FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-
-    #if HAS_FAN1
-      SET_OUTPUT(FAN1_PIN);
-      #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(FAN1_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
-      #endif
-      #if ENABLED(FAN_SOFT_PWM)
-        soft_pwm_fan[1] = fanSpeedSoftPwm[1] / 2;
-      #endif
+    #if ENABLED(FAN_SOFT_PWM)
+      soft_pwm_fan[0] = fanSpeedSoftPwm[0] / 2;
     #endif
+  #endif
 
-    #if HAS_FAN2
-      SET_OUTPUT(FAN2_PIN);
-      #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(FAN2_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
-      #endif
-      #if ENABLED(FAN_SOFT_PWM)
-        soft_pwm_fan[2] = fanSpeedSoftPwm[2] / 2;
-      #endif
+  #if HAS_FAN1
+    SET_OUTPUT(FAN1_PIN);
+    #if ENABLED(FAST_PWM_FAN)
+      setPwmFrequency(FAN1_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
+    #if ENABLED(FAN_SOFT_PWM)
+      soft_pwm_fan[1] = fanSpeedSoftPwm[1] / 2;
+    #endif
+  #endif
 
-  #endif // FAST_PWM_FAN || FAN_SOFT_PWM
+  #if HAS_FAN2
+    SET_OUTPUT(FAN2_PIN);
+    #if ENABLED(FAST_PWM_FAN)
+      setPwmFrequency(FAN2_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+    #endif
+    #if ENABLED(FAN_SOFT_PWM)
+      soft_pwm_fan[2] = fanSpeedSoftPwm[2] / 2;
+    #endif
+  #endif
 
   #if ENABLED(HEATER_0_USES_MAX6675)
 
@@ -1068,16 +1064,44 @@ void Temperature::init() {
   #endif
 
   #if HAS_AUTO_FAN_0
-    pinMode(EXTRUDER_0_AUTO_FAN_PIN, OUTPUT);
+    #if EXTRUDER_0_AUTO_FAN_PIN == FAN1_PIN
+      SET_OUTPUT(EXTRUDER_0_AUTO_FAN_PIN);
+      #if ENABLED(FAST_PWM_FAN)
+        setPwmFrequency(EXTRUDER_0_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      #endif
+    #else
+      pinMode(EXTRUDER_0_AUTO_FAN_PIN, OUTPUT);
+    #endif
   #endif
-  #if HAS_AUTO_FAN_1 && (EXTRUDER_1_AUTO_FAN_PIN != EXTRUDER_0_AUTO_FAN_PIN)
-    pinMode(EXTRUDER_1_AUTO_FAN_PIN, OUTPUT);
+  #if HAS_AUTO_FAN_1 && !AUTO_1_IS_0
+    #if EXTRUDER_1_AUTO_FAN_PIN == FAN1_PIN
+      SET_OUTPUT(EXTRUDER_1_AUTO_FAN_PIN);
+      #if ENABLED(FAST_PWM_FAN)
+        setPwmFrequency(EXTRUDER_1_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      #endif
+    #else
+      pinMode(EXTRUDER_1_AUTO_FAN_PIN, OUTPUT);
+    #endif
   #endif
-  #if HAS_AUTO_FAN_2 && (EXTRUDER_2_AUTO_FAN_PIN != EXTRUDER_0_AUTO_FAN_PIN) && (EXTRUDER_2_AUTO_FAN_PIN != EXTRUDER_1_AUTO_FAN_PIN)
-    pinMode(EXTRUDER_2_AUTO_FAN_PIN, OUTPUT);
+  #if HAS_AUTO_FAN_2 && !AUTO_2_IS_0 && !AUTO_2_IS_1
+    #if EXTRUDER_2_AUTO_FAN_PIN == FAN1_PIN
+      SET_OUTPUT(EXTRUDER_2_AUTO_FAN_PIN);
+      #if ENABLED(FAST_PWM_FAN)
+        setPwmFrequency(EXTRUDER_2_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      #endif
+    #else
+      pinMode(EXTRUDER_2_AUTO_FAN_PIN, OUTPUT);
+    #endif
   #endif
-  #if HAS_AUTO_FAN_3 && (EXTRUDER_3_AUTO_FAN_PIN != EXTRUDER_0_AUTO_FAN_PIN) && (EXTRUDER_3_AUTO_FAN_PIN != EXTRUDER_1_AUTO_FAN_PIN) && (EXTRUDER_3_AUTO_FAN_PIN != EXTRUDER_2_AUTO_FAN_PIN)
-    pinMode(EXTRUDER_3_AUTO_FAN_PIN, OUTPUT);
+  #if HAS_AUTO_FAN_3 && !AUTO_3_IS_0 && !AUTO_3_IS_1 && !AUTO_3_IS_2
+    #if EXTRUDER_3_AUTO_FAN_PIN == FAN1_PIN
+      SET_OUTPUT(EXTRUDER_3_AUTO_FAN_PIN);
+      #if ENABLED(FAST_PWM_FAN)
+        setPwmFrequency(EXTRUDER_3_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      #endif
+    #else
+      pinMode(EXTRUDER_3_AUTO_FAN_PIN, OUTPUT);
+    #endif
   #endif
 
   // Use timer0 for temperature measurement