diff --git a/Marlin/pinsDebug.h b/Marlin/pinsDebug.h
index eb5584d65e15c521577329fe0c0d1771098c275d..b4016437a8ee9fba1ccf7ae3d4e71d5fddc78c83 100644
--- a/Marlin/pinsDebug.h
+++ b/Marlin/pinsDebug.h
@@ -22,6 +22,10 @@
 
 bool endstop_monitor_flag = false;
 
+#if !defined(TIMER1B)    // working with Teensyduino extension so need to re-define some things
+  #include "pinsDebug_Teensyduino.h"
+#endif
+
 #define  NAME_FORMAT "%-28s"   // one place to specify the format of all the sources of names
                                // "-" left justify, "28" minimum width of name, pad with blanks
 
@@ -683,7 +687,9 @@ static bool pwm_status(uint8_t pin) {
     #if defined(TCCR1A) && defined(COM1A1)
       PWM_CASE(1,A);
       PWM_CASE(1,B);
-      PWM_CASE(1,C);
+      #if defined(COM1C1) && defined(TIMER1C)
+        PWM_CASE(1,C);
+      #endif
     #endif
 
     #if defined(TCCR2A) && defined(COM2A1)
@@ -694,7 +700,9 @@ static bool pwm_status(uint8_t pin) {
     #if defined(TCCR3A) && defined(COM3A1)
       PWM_CASE(3,A);
       PWM_CASE(3,B);
-      PWM_CASE(3,C);
+      #if defined(COM3C1)
+        PWM_CASE(3,C);
+      #endif
     #endif
 
     #ifdef TCCR4A
@@ -778,13 +786,15 @@ static void pwm_details(uint8_t pin) {
         else if (TIMSK1 & (_BV(TOIE1) | _BV(ICIE1))) err_prob_interrupt();
         else can_be_used();
         break;
-      case TIMER1C:
-        TIMER_PREFIX(1,C,4);
-        if (WGM_TEST2) err_is_counter();
-        else if (TEST(TIMSK1, OCIE1C)) err_is_interrupt();
-        else if (TIMSK1 & (_BV(TOIE1) | _BV(ICIE1))) err_prob_interrupt();
-        else can_be_used();
-        break;
+      #if defined(COM1C1) && defined(TIMER1C)
+        case TIMER1C:
+          TIMER_PREFIX(1,C,4);
+          if (WGM_TEST2) err_is_counter();
+          else if (TEST(TIMSK1, OCIE1C)) err_is_interrupt();
+          else if (TIMSK1 & (_BV(TOIE1) | _BV(ICIE1))) err_prob_interrupt();
+          else can_be_used();
+          break;
+      #endif
     #endif
 
     #if defined(TCCR2A) && defined(COM2A1)
@@ -819,13 +829,15 @@ static void pwm_details(uint8_t pin) {
         else if (TIMSK3 & (_BV(TOIE3) | _BV(ICIE3))) err_prob_interrupt();
         else can_be_used();
         break;
+      #if defined(COM3C1)
       case TIMER3C:
-        TIMER_PREFIX(3,C,3);
-        if (WGM_TEST2) err_is_counter();
-        else if (TEST(TIMSK3, OCIE3C)) err_is_interrupt();
-        else if (TIMSK3 & (_BV(TOIE3) | _BV(ICIE3))) err_prob_interrupt();
-        else can_be_used();
-        break;
+          TIMER_PREFIX(3,C,3);
+          if (WGM_TEST2) err_is_counter();
+          else if (TEST(TIMSK3, OCIE3C)) err_is_interrupt();
+          else if (TIMSK3 & (_BV(TOIE3) | _BV(ICIE3))) err_prob_interrupt();
+          else can_be_used();
+          break;
+      #endif
     #endif
 
     #ifdef TCCR4A
@@ -942,4 +954,3 @@ inline void report_pin_state_extended(int8_t pin, bool ignore) {
   pwm_details(pin);
   SERIAL_EOL;
 }
-
diff --git a/Marlin/pinsDebug_Teensyduino.h b/Marlin/pinsDebug_Teensyduino.h
new file mode 100644
index 0000000000000000000000000000000000000000..fc5c03abeec9c1840bd40002667a80ca0d618b89
--- /dev/null
+++ b/Marlin/pinsDebug_Teensyduino.h
@@ -0,0 +1,110 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2017 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+ 
+//
+//  some of the pin mapping functions of the Teensduino extension to the Arduino IDE
+//  do not function the same as the other Arduino extensions
+//
+
+
+#define TEENSYDUINO_IDE
+
+//digitalPinToTimer(pin) function works like Arduino but Timers are not defined
+#define TIMER0B 1
+#define TIMER1A 7
+#define TIMER1B 8
+#define TIMER1C 9
+#define TIMER2A 6
+#define TIMER2B 2
+#define TIMER3A 5
+#define TIMER3B 4
+#define TIMER3C 3
+
+// digitalPinToPort function just returns the pin number so need to create our own
+#define PA 1
+#define PB 2
+#define PC 3
+#define PD 4
+#define PE 5
+#define PF 6
+
+#undef digitalPinToPort
+
+const uint8_t PROGMEM digital_pin_to_port_PGM[] = {
+  PD, // 0  - PD0 - INT0 - PWM
+  PD, // 1  - PD1 - INT1 - PWM
+  PD, // 2  - PD2 - INT2 - RX
+  PD, // 3  - PD3 - INT3 - TX
+  PD, // 4  - PD4
+  PD, // 5  - PD5
+  PD, // 6  - PD6
+  PD, // 7  - PD7
+  PE, // 8  - PE0
+  PE, // 9  - PE1
+  PC, // 10 - PC0
+  PC, // 11 - PC1
+  PC, // 12 - PC2
+  PC, // 13 - PC3
+  PC, // 14 - PC4 - PWM
+  PC, // 15 - PC5 - PWM
+  PC, // 16 - PC6 - PWM
+  PC, // 17 - PC7
+  PE, // 18 - PE6 - INT6
+  PE, // 19 - PE7 - INT7
+  PB, // 20 - PB0
+  PB, // 21 - PB1
+  PB, // 22 - PB2
+  PB, // 23 - PB3
+  PB, // 24 - PB4 - PWM
+  PB, // 25 - PB5 - PWM
+  PB, // 26 - PB6 - PWM
+  PB, // 27 - PB7 - PWM
+  PA, // 28 - PA0
+  PA, // 29 - PA1
+  PA, // 30 - PA2
+  PA, // 31 - PA3
+  PA, // 32 - PA4
+  PA, // 33 - PA5
+  PA, // 34 - PA6
+  PA, // 35 - PA7
+  PE, // 36 - PE4 - INT4
+  PE, // 37 - PE5 - INT5
+  PF, // 38 - PF0 - A0
+  PF, // 39 - PF1 - A1
+  PF, // 40 - PF2 - A2
+  PF, // 41 - PF3 - A3
+  PF, // 42 - PF4 - A4
+  PF, // 43 - PF5 - A5
+  PF, // 44 - PF6 - A6
+  PF, // 45 - PF7 - A7
+  PE, // 46 - PE2 (not defined in teensyduino)
+  PE, // 47 - PE3 (not defined in teensyduino)
+};
+
+#define digitalPinToPort(P) ( pgm_read_byte( digital_pin_to_port_PGM + (P) ) )
+
+// digitalPinToBitMask(pin) is OK
+
+#define digitalRead_mod(p)  digitalRead(p)   // Teensyduino's version of digitalRead doesn't
+                                             // disable the PWMs so we can use it as is
+
+// portModeRegister(pin) is OK