From ecd490ed49e2d6d5e1754fda4cccf7f19cda8e70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Br=C3=A1zio?= <jbrazio@gmail.com>
Date: Sun, 15 May 2016 22:45:08 +0100
Subject: [PATCH] Bugfix: iteration invokes undefined behavior

---
 Marlin/temperature.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 76bab525f..63db7e9ea 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -342,7 +342,7 @@ int Temperature::getHeaterPower(int heater) {
       EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_2_AUTO_FAN_PIN ? 2 : 3
     };
     uint8_t fanState = 0;
-    for (int f = 0; f <= 3; f++) {
+    for (int f = 0; f <= EXTRUDERS; f++) {
       if (current_temperature[f] > EXTRUDER_AUTO_FAN_TEMPERATURE)
         SBI(fanState, fanBit[f]);
     }