Nortek Security & Control LLC/GTO Access MMT103 User Manual

RED LED

LEARN BUTTON

Lights Flash

RED LED

Flash

DESCRIPTION:
The MMT103 Code Safe digital transmitter is a wireless radio control designed for use with Mighty Mule 

garage door openers and can also be programmed to your Mighty Mule gate openers.  One remote for 

two or three devices.
Each of the three transmitter buttons will send a unique code when pressed. All buttons can be used to 

activate an individual Mighty Mule garage door opener, multiple Mighty Mule garage door openers or 

Mighty Mule garage door opener(s) and gate opener(s).

3-BUTTON REMOTE TRANSMITTER

Press the operator’s LEARN button until the 

operator’s red LED flashes once and the light turns 

on. A remote must be added while the light is still on 

(15 seconds).
Send a signal from the desired button on the remote. 

The operator’s light and the red LED will flash once if 

the remote was added.

Repeat to program additional buttons for other garage 

door openers.
After programming, test the transmitter from various 

locations. Be sure the door or gate areas are clear. 

Activate the transmitter and verify that the receiver 

triggers the opener(s).

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PRINTER’S INSTRUCTIONS: 

INSTR, INSTL, MMT103 - GTO P/N: 10015841 A - INK: BLACK - MATERIAL: 20# MEAD BOND - SIZE: 8.500” x 5.500” - SCALE: 1-1

If you have a Mighty Mule gate opener, you can program one of the buttons to 
open the gate also.

Press and hold button 1 and button 3 at the same time for 5 seconds. The LED 
will turn on, then release the buttons.  

Press and release the button that you want to learn the gate opener code to.

Hold the gate opener transmitter with the front/top facing the side of the 
MMT103. Press the button on the gate opener transmitter and the LED on the 
MMT103 will blink twice when it has successfully learned the code.  

The button you programmed will now transmit the gate opener code as indicated 
by the LED being solid on when the button is pressed.

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Button #1

LED

Button #3

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Press and release the button you 
want to learn the gate operator code

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Press and hold the gate operator transmitter button 
until the LED on the MMT103 blinks twice 

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LED

Press and hold button 1 and button 3 at the same time for about 5 
seconds. The LED will turn on, then release the buttons.  

Press and hold the button you want to delete a code from for 5 seconds, 
then the LED will blink twice indicating the DIP switch code was 
successfully removed.  

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Press and hold the button you want 
to delete a code from for five seconds.

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Button #1

LED

Button #3

Printed in China for GTO Access Systems, LLC.

MIGHTY MULE LIMITED WARRANTY
This product is warranted to the consumer against defects in material and workmanship for one year from the date of purchase. This warranty applies 

to first retail buyers of new devices. Mighty Mule will repair, or at its option, replace, any device it finds that requires service under this warranty, and 

will return the repaired or replaced device to the consumer at the Might Mule’s cost. For warranty service and shipping instructions contact Mighty 

Mule Tech Service. Devices must be sent to Mighty Mule for service at owner’s expense. The remedies provided by this warranty are exclusive. 

Implied warranties under state law are to the one year period of this written warranty. Some states do not allow limitations on how long an implied 

warranty lasts, so the above limitation may not apply to you. In order to be protected by this warranty, save your proof of purchase and send copy with 

equipment should repair be required. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
All products returned for warranty service require a Return Product Authorization Number (RPA#). Contact Mighty Mule Technical Services at 1-800-

543-1236 for an RPA# and other important details.

When the red light on the transmitter glows dimly, or fails to light at 
all when the transmitter is activated, the batteries need replacing.

Twist a coin, visor clip or screw drive in slot to open case.

Lift off top of case.

Carefully remove the circuit board.

Remove old battery and properly dispose them.

Replace battery with new Type 2032 battery – PLUS SIDE UP.

Re-assemble the transmitter.

Mighty Mule® is the retail brand of GTO Access Systems, LLC

3121 Hartsfield Road • Tallahassee, FL 32303

Mighty Mule Sales: 800-543-4283 • Fax 850-575-8912

Mighty Mule Technical Service 800-453-1236

For more information on Mighty Mule’s full line of Garage Door Openers, Gate Openers, Accessories and 

Access Controls, visit www.mightymule.com

KEEP BATTERIES OUT REACH OF CHILDREN. Swallowing batteries can lead to serious injury or death. If you suspect 
someone has swallowed a battery, go to the hospital immediately. Do not induce vomiting or eat or drink anything. 
For more information, call the National Battery Ingestion Hotline: 202-625-3333. 
The battery identification number for this product is CR2032.

WARNING: Changes, modifications or adjustments not expressly approved by GTO Access Systems, LLC could void the user’s authority to operate 

this equipment. There Are No User Serviceable Parts.

NOTICE: This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause 

harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

This device complies with Industry Canada License-exempt RSS standard. Operation is subject to the following two conditions: (1) this device may not 

cause harmful interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device.

If a remote is already programmed to the opener and you want to delete it, follow the same procedure as PROGRAMMING THE REMOTE 

above. The opener will recognize the remote and delete it from memory. The RED LED and LIGHT will blink 4 times to show the REMOTE was 

successfully deleted.