Dec 152011

Had this problem with my garage door opening at random times. Figured it was the external fixed code receiver, so I replaced everything with rolling code receivers, with matching transmitters obviously. So big was my surprise when a friend visited and my garage door opened as he was locking his car. Turns out I forgot about the integrated receiver on the garage opener. And this turned out to be a fixed code one as well. Had no luck in getting any information from the company who installed the garage opener about disabling the receiver, and google led me to other people who had the same experience. So firstly I cut the aerial off the built-in, which limited the range of the old transmitter, but it was still triggering if I got closer to the unit. Turns out the solution was even simpler. Just put the integrated receiver into learning mode with a simple jumper (connect middle and B as per the image) and no remote will ever trigger it again. Problem solved.

  43 Responses to “Coromaster Mach II hack”

  1. I have the same problem with my Mach II. My niece’s car remote opens my garage door. It had opened randomly as well. I now keep it electronically locked. How do you change from fixed code to rolling code. Please advise if this is a DIY and cost.


  2. Electronically locking the motor defeats the purpose of having it in the first place. It’s an easy DIY job:
    1. buy a rolling code receiver, eg. RX1-RC as per ET receivers;
    2. buy as many matching remotes as you need, eg. TX1-RC (or TX2-RC or TX4-RC if you need to change more channels) as per ET remotes;
    3. install the receiver: tap 0V/ground and 12V from the back of the Mach II, jump common on receiver to 0V on receiver and wire NC on the receiver to the matching pin on the back of the Mach II;
    4. run through the installation manual of the receiver to learn the remote(s) on the receiver;
    5. test, after disabling the electronic lock of course;
    6. disable the on-board receiver on the Mach II as per my article.
    If you need help with the wiring, give me a shout. Good luck.

    • Hi PI

      I have a simple problem and it appears you can help.

      I just need to reset my garage door as it opens and closes at wrong point. I have to manually stop it. BTW it is a Coroma Mach II.

      Your help will be appreciated.

      • Press and hold the reset button on the unit for a few seconds. You’ll know it’s long enough when the motor engages, at which time you can release the reset button. It will open and close the door a few times to detect the stops. If you do not have a hard stop on the pipe (I have a big bolt through the pipe on mine) to prevent the arm from stopping as it approaches the motor, you need to press your remote or wall button the first time the arm reaches the position you want it to stop. If you do have a hard stop on the pipe, you don’t have to do this. Once it has run through the stop detection process, the door should be closed and you might notice that the one chain is hanging a little bit low. I do a very quick press of the remote or the wall button to tell the motor to pick up the slack. Good luck.

        • Thank you for this forum,
          I recently purchased a Coromaster Mack II second hand, and this forum was the only useful site related to this garage door opener I could find.

          I am experiencing a similar problem than Cobus and attempted the steps described above, but it does not work in my Case.

          When I press the program button the motor starts running immediately, there is no delay before it starts and no change when I keep the button in, the only way stop the motor is by removing the power supply to the motor, it does not even respond to the push button or external remote receiver.

          Does this sound normal, maybe I am missing a jumper setting?

          Any advice will be appreciated.

          Best regards.

          • Francois, the only visible jumper that I have on mine, apart from the programming jumper as described in this article, is the one on the LD position, which is next to the PRG button on left. I haven’t looked under the hood to see if there are additional jumpers there. Do you know whether the system worked when you bought it? Maybe there’s some logic error on the motherboard and you were sold a dud unit? I’m also assuming that you wired the external push button and receiver correctly. 🙂

  3. Thanks PI. Your point 3 is a bit cryptic to me (i’m not techno minded). If you have moment please explain in layman terms. Your advice much appreciated.


  4. I’ve posted a new article with more details. Good luck.

  5. Thanks a bazillion PI. That looks fairly straightforward. Your assistance much appreciated.

  6. hi how do i program a remote

    • If it’s the original remote that shipped with the Mach II (black with orange backplate), put the receiver into learning mode as indicated in the picture above. Then press the button on the remote. Remove the jumper again and the button should work. NOTE: these remote controls are not secure and the garage motor can be triggered by something as simple as someone locking or unlocking a car, so I’d suggest you rather override the receiver on the garage opener as per my other post.

  7. Hi Pi

    Been through your blog. Very informative. Haven’t experienced the random opening (yet) with the mach II. Have noted the solution as it can be a security problem. Will attempt to change to rolling receiver. Have the following problem however which you may be able to help…garage does not open consistently. Then i have to switch off, pull cord, switch on and open with the remote. Then for a few days its ok and then does it again. Your post on october 12 talks about resetting the stops. Currently the chain is hanging quite low when the door is closed and the motor seems to have a problem engaging when you press the button to open. Will resetting the open and close stops work or is there another solution. What do you mean by “I do a very quick press of the remote or the wall button to tell the motor to pick up the slack”.

    Any help would be most appreciated


    • Firstly, please note that I’m not a garage door expert or professional, so all my comments are based on my own experiences. In my case, after resetting the stops, or after a power failure, the chain hangs a little bit lower than usual; drooping roughly 10cm+ at the lowest point. In my opinion, it’s not necessary for the motor to exert that much pressure to keep the door closed, since we have gravity on our side. A quick press on the remote control or the wall button lets the motor exert slightly less pressure on the chain and the drooping gets closer to about 5-7cm (measured by eyeball). If yours is a lot more, it might be that your chain is either worn or stretched and might need to be replaced. However, this is not something I’ve needed to do, even after 11 years of use. If the chain hangs fairly straight (drooping by roughly 3-5cm, again measured by eyeball) when the door is open, or even halfway open, then it might be a simple case of resetting the stops, as described in an earlier post. If the chain droops very low when the door is open, it might need replacing or something else is off there. Speak to a professional about that.

  8. I have the identical problem with my daughter’s coroma mach ll garage door opener. Got a guy in who fitted an additional, I think an ET product receiver unit, with a new remote. Surprisingly the next morning the garage door was open again, activated by someone else’s remote. The guy who has installed the new receiver, never disconected or bypassed the original coroma receiver and the door still opens with the old and the new remote,Somehow I think the coroma receiver should be disconnected. Would you please beso kind as to guide me how to de-activate the coroma receiver.
    Thanking you,

    • Sounds like the guy only removed the additional receiver and did nothing to the onboard receiver. The solution is simple as per the last line of my original post: jumper the onboard receiver into learning mode and you’ll notice the old remote will no longer trigger the door, nor any other external sources.

  9. Thanks so much for your help Pi. My garage door is sorted. Its opening with confidence. No more holding thumbs.

  10. Hi,

    My boss has asked me to program his new remote. I have been reading the correspondence. Confirm there is a learn jumper that has to be put it place. Then press the remote.

    If this is correct where will I find it on the motor.

    My garage does not have this system.

    cheers Pierre

  11. Hi

    My remote to my coromaster mach II is not working and i would like to reprogramme the remote. I’ve googled but cant seem to find a manual. Anybody perhaps have a copy of the manual pls?

    • If it’s the default remote (black front, orange back) that you got with the Coromaster, you can program it by connecting the programming jumper, as shown in the diagram in the article. Then press the remote button and remove the jumper again. The remote should now work. However, the Coromaster system is using a fixed code system, so it’s NOT secure and can be triggered by something as simple as a car remote. I’d advise you to convert your system to something that uses rolling code, as per my other article. And no, haven’t seen a manual for this system on the internet either.

  12. Had all that done by a automated company but my range is now very short. I sometimes stand outside my garage for more than fifteen minutes trying to open my door and unless I get out of the car and step close to the door, it opens.
    Please assist if you can.
    Your advice will be greatly appreciated.

    • I’ve had something similar at a neighbour. Still unsure why it was doing that, but it seemed as if something was interfering with the signal to the external receiver. What I had to do was to take the external receiver further away from the opener by adding a length of cable (I used 3m) between the external receiver and the opener. Wire it up this way and move the receiver around in your garage until you get the best range.

  13. Hello,

    Thank you for this forum, it’s been quite informative.

    Would you know how to remove the delay on closing? When pressing the remote to close the door, there s about a 5 second delay before the door closes and I want to remove / disable it

    Thank you

    • You’re welcome! As far as I know, that delay is a safety feature. During this 4-5 seconds, the light flashes 3 times to alert people that the door is about to close. If you see no light, you might need to change the bulb. Use the lowest wattage one you can find, or you’ll melt the plastic in front of it.

  14. I have a coroma mach 11 and both remotes are broken where can i buy new ones

    • You might be able to buy remotes at a security shop, but I actually doubt it, since the Coromaster is ancient. However, I’d strongly suggest you follow my other post on how to convert your garage opener to rolling code to improve your own security.

  15. Hi guys, i hope you can help me. I have a coromaster 2000 converted to rolling code with the rx1-rc.problem is that the door does not open anymore it seems to only want to close, and i had to remove it from the motor. When i press on the remote, the motor makes a turn but is already open and it should be closing. What can this be? Is it serious and should i get a new motor? Any help will be apreciated.thanx. Keep up the good work

    • Hi, does the door operate normally without the rx1-rc receiver? If so, you might have connected the receiver incorrectly. It must be connected to the NO (normally open) terminal, not the NC (normally closed) terminal. If the door doesn’t operate normally without the extra receiver, it might have lost its programmed stops. I have a neighbour with the 2000 model, but I haven’t been able to determine how to reset the stops on that model, as the reset button doesn’t operate in the same way as the Mach2 model which I have. In summary, first ensure the door is operating normally without the extra receiver. Once that’s sorted, adding the extra receiver is easy. 🙂

  16. I have a big problem! I just bought a new rempte for my coromaster mach ii but i have no idea how to program it, i have two garage doors and a gate to go onto the remote, think its called a nova remote, please help!

    • Hi, did you buy a Nova receiver with the Nova remote? And a receiver for the gate too? Or did you have other Nova remotes (and receivers) already? The Nova remote should come with a short manual on how to program it/add it to an existing receiver. Either way, you’ll have to give me more details on what you have already and what you want to accomplish. Once I have that, I’ll be able to give you some advice on how to accomplish that.

  17. Hi pi

    I had the remotes but no receivers. ive also learnt on the net how to program it with the learn button but i cannot locate it on the actual coroma motors. I will also have to put my centurion d5 outside gate on the control.

    • Firstly, I have no idea what receivers you have connected, so you may need to expand a bit on your last answer. Also have no idea what the Nova remotes are, since I’ve never had to deal with them before.

      However, the Centurion D5 gate motor has a built-in rolling code receiver, so I hope your Nova remotes are compatible with that receiver. If so, it’s a matter of programming the Nova remote(s) onto the gate motor. If not, you’ll need to add a compatible receiver to the gate motor.

      Likewise with the Coromaster Mach II, which has a built-in fixed code receiver, which you’d want to disable as I explained in my 1st post, as it can be triggered by something as simple as a car alarm remote. So you might have to add a Nova compatible receiver to the Coromaster as I explained in my 2nd Coromaster post.

      If you can give me full details on what you have, I would be able to advise you on how to accomplish the above, assuming you’re handy with a screwdriver. If not, you might want to get a professional to assist.

  18. Thanks a million. Got a new neighbour with vw that kept opening my garage door. Replaced as per your instructions. All working fine now.

  19. Thanx for the instructions! I’m just a bit confused, should the jumper that enables the learning mode be left in place permanently ? A locksmith did mine, but I think they ignored the internal receiver as you mentioned. I see on the other side of the block where the wires connect (your pic just doesnt cover that far) there is a jumper, and the line of the 2 pins is perpendicular to the pins you are referring to.
    I’m not sure if that is a storage place for the jumper and that it should be removed and placed on yours,
    or if I should just rather get a new jumper ?

    • The single jumper next to the LED and PRG button is labeled as “load setting” on mine, so I’d suggest you leave that jumper alone. And yes, you need to put the internal receiver in learning mode on a permanent basis. By doing this, the internal receiver will never act on trigger actions by other remotes, so you effectively disable the internal receiver. These jumpers are the same as the ones commonly found in PC’s, so it should be easy to source.

  20. Hi There, Could you please tell me how to remove all remotes that were programed to a Coromaster garage door opener as I had a set of house keys stolen and would like to disable that remote by clearing them all and then re programming the others I still have.

    Many thanks

    • Are you using the on-board receiver? If so, I’d really advise you to rather override that receiver (it’s fixed code and can be easily triggered by a car remote) and use an external receiver. See some of my other posts on how to override and replace it. If you already have an external receiver, it would depend entirely on the brand and model of that receiver, as each one has their own reset method.

      • Thanks for your speedy reply – At the moment it is just using the on-board receiver.
        I will look through your post on how to change to an external receiver – do you recommend any particular one? In the mean time before I get an external one could you tell me how to remove all remotes on the on-board receiver, just to give me piece of mind that someone is not going to pitch up with a working remote before I’ve had a chance to change to an external receiver.

        Thank you

        • I’m actually not sure how to reset the list of valid remotes on the on-board receiver. If you want peace of mind, you can put the receiver into learning mode (as per this post). If you have a button on the wall you can press and hold that to put the motor into locked mode, which will prevent it from operating at all until you unlock it via the same method. Note that you will have to have an alternative access method into the garage, eg. a door into the house, since all your remotes will stop working. Your best option is still an external receiver. I’ve used ET receivers (and remotes) in the past, but any rolling code one will do. Note that you will have to replace all your remotes as well and these remotes must match the receiver, so it’s best you replace them as a set.

  21. Thanks very much for the fixed remote solution.
    Both my wife and daughter have Audi Q3 cars. Garage door does its own thing. It surprises me that the original installers don’t bother to disable the fixed receiver when you specify the rolling code ones!
    Raises an interesting question, would you have a claim against them for any loss due to what is undoubtedly absolute negligence?

    Thanks once again for sharing!!

    • You’re welcome, Mike. Not a lawyer, so can’t comment on the negligence question. I’d guess they’ll simply shrug their shoulders and claim you didn’t specify that the old receiver had to be disabled.

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