Reset G5/G6 Transmitters

Note: with the recent Spike-App issues, I have updated this blog post with current information for clarity. This app works for both G5 and G6.

First, let me preface by saying that I adore, love, respect, and covet my Dexcom system.  It gives us a stability with type 1 diabetes that we would never be able to do without now.  But what I’m about to tell you is a bit of a hack on their system.

There’s been one thing I really have not enjoyed about moving from the G4 to the G5 system about four months ago.  The G4 transmitters were warrantied for 6 months, but usually the battery in those would go for a year…meaning we had the opportunity for much of the transmitter’s useful life to have a backup on the shelf at all times.  If the G4 transmitter failed for any reason, we could pick one off our shelf and not stress about how long it would take to get a new one.  Overseas travel and 2-week long diabetic summer camps were not a big deal…we could pack a backup.

Then we switched to the G5 system at the beginning of this year so that Anna didn’t have to carry a receiver while she did track team workouts.  This dramatically improved the likelihood that she would stay in good BG range during workout because our DIY loop system would have BGs available the entire workout to help her insulin needs.  If Anna had to carry a receiver during track workouts, that would’ve been the straw that broke the camel’s back in terms of diabetes gear she was willing to manage.

So, we’ve loved the G5 and G6.  It has worked well; not really having any problems with signal loss, BGs are accurate, we have enjoyed Clarity reports.  All good EXCEPT those G5/G6 transmitters being shut-off by Dexcom  at 112 days.  At 90 days, you get a warning and your warranty is up.  At 112 days, your transmitter is artificially shut-off even though the batteries have some useful life left.  How much life?  Well, that depends, but for most users it is about a couple more months of life.

The problem with this system is that my insurance covers 2 transmitters in one order every 6 months.  So, for the first 90 days (3 months) after a transmitter order, I will nicely have a backup sitting on the shelf in case things go wrong.  BUT, for the next 3 months, I will have no backups on the shelf.  If that second transmitter dies early, I would have to wait for Dexcom to send us a new one.  If we were overseas or traveling, this could be very inconvenient.  I definitely won’t have one to send with Anna to her 2 weeks of summer camp based on how I can forecast our insurance refills already.

And here’s the really great news.  You can now reset the clock on that 112 day shut-off by building an app that Pete Schwamb released, building on Nate Racklyeft’s work of decoding the Dexcom protocol.  This doesn’t buy you heaps of extra time…as the battery will only go for about 2 more months (maybe even less?) past 112 days…but that could be just enough time to start to be able to keep a backup transmitter on the shelf for longer between orders.

Another really good plus?  You can use this reset on G5/G6 transmitters that have had their batteries replaced AND still use the Dexcom official app…you won’t have to try to use a different app (like Spike-App or X-drip+).


What you will need:

  • iPhone (iOS 11.1 minimum, (this should also work on iPod touch 6th generation or newer…I just don’t have one laying around to confirm)
  • Apple computer (macOS 10.13.6 High Sierra  or 10.14.3 (or newer) Mojave)
  • Xcode 10.1 or 10.2 (or newer)
  • Apple ID email

IMPORTANT BEFORE WE GO ANY FUTHER…the version of iOS you have on your phone will make a difference in how you proceed. So, take a minute to check what iOS version you have in your iPhone Settings -> General -> About -> Software Version.

**IF you have iOS 12.2, you will have to use Xcode 10.2. No way around that. And in order to use Xcode 10.2, you will need macOS Mojave 10.14.3 at a minimum. High Sierra and Xcode 10.1 will not work for installing on iPhones that have iOS 12.2.**

Check to see if you need to update your macOS based on the version of iOS you have, as just discussed.  You can check your macOS by clicking the apple logo in your computer display’s upper left corner and selecting About this Mac.   If you are due for an update, click the Software Update button.

Now that you have the macOS updated (to Mojave if you have iOS 12.2), we need to add a little program called Homebrew.

Homebrew is a program that will allow us to install the needed packages to build Loop.  Open the Terminal application on your computer.  It is located in the Applications folder, and then look in the Utilities subfolder for the Terminal application.

Terminal app is very plain looking when you open it.  That is normal. Copy and paste the line below into Terminal prompt.  Take the copy all the way from the first / to the last ”  Press return after you paste it into Terminal app.

/usr/bin/ruby -e "$(curl -fsSL"

There will be a prompt asking if you want to continue.  Press return to continue, then it will prompt for your password.  Enter your computer user password (don’t worry, Terminal app doesn’t show keystrokes when you enter passwords, but it is still reading your typing).

Wait while the script does its thing…you’ll see info scroll by and then it will pause for awhile.  Eventually, it will be done and you’ll see something that says “Installation successful” and you’ll have a ready Terminal prompt again.

Last step is to copy and paste this red line below into Terminal app:

brew install carthage

This should result in the installation of Carthage version 0.33. (If you have an older version of Carthage already installed because of previous work on your computer, the command is brew update && brew upgrade carthage to get Carthage updated to the new version you’ll need.)  You’re all done with the Terminal application now.  You’re done with it. 

You can now download and install the app called Xcode from the App Store on your computer.  Xcode 10.2 is what you need for iOS 12.2 users. When the installation is finished, open Xcode by double-clicking on it from your Applications list. And yes…the download and installation of Xcode can take a long time depending on internet speed and computer. It takes upwards of 45 minutes for many people.

Note: If this is the first time you are opening Xcode, you may get an initial message telling you that Xcode is installing command line tools.  Please let that run and complete the installation.  Command Line tools are a needed installation.

Go to the Xcode menu on the top of your screen, and click on Xcode and then Preferences...

Within Preferences, click on the Accounts tab and then the + button in the bottom left corner to add an account.  You are going to add an Apple ID type account.

Enter in your Apple ID email and password.  This process automatically makes a free Apple Developer account associated with your Apple ID email.  The account will show up in your Xcode preferences now with your name and (personal team) as a suffix in the name.  Once your account is added, close the Preferences screen by clicking on the red circle in the upper left corner.

Now we need to download the code for the ResetTransmitter app. The code that will work will be dependent on your Xcode version.

Click here to download ResetTransmitter App’s code

Open your downloads folder and navigate to the CGMBLEKit-3.0 folder that you downloaded. Inside that folder, find the file CGMBLEKit.xcodeproj file.  Double-click on that file and the project will open in Xcode automatically.

Click on the open button when the message appears asking:

“CGMBLEKit” is a project downloaded from the Internet. Are you sure you want to open it?

{Take the time now while the project opens to plug in your iPhone to the computer using your lightning cable.  Please accept any prompts about trusting your computer and unlock your phone so that it stays awake through the build process of the app that we are about to finish.}

Now click on the CGMBLEKit at the top of the left column, and then click on the small box as shown on the screenshot below to show the list of “Targets” below it.  Select the “ResetTransmitter” target.

Now, look at the screenshot above.  See that part highlighted in blue? You will need to change the loopkit part of the Bundle Identifier to a unique-to-you word or phrase (no spaces).  Make sure that when you make the edit, you do not delete the period before and after.

Once you have the name edited, then go down to the Team section and select your (personal team) signing name from the drop down menu selection.  [Note: if you have a paid developer account, you can use that signing name instead.]

After you finish signing, a Provisional Profile will automatically be created and you’re close to done.

If you see a prompt under the status area below the Team about your device not being registered, please click on the Register Device button provided there to register the iPhone to your developer account (see screenshot below).

Now, navigate up to the top of your window and select two things; one from the left side of the box you’re going to select ResetTransmitter and from the pop-out, you’re going to select your phone’s name from the very top of the device list (not just your phone model…you want to go all the way to the top of the list for your phone’s name).

Stop and double check….most common mistake is forgetting to select ResetTransmitter as shown in the screenshot below and mentioned above.  Do not leave the selection on CGMBLEKit…if you do, your app will build properly nor will it appear on your phone.

If your phone/device name has (untrusted) after the name (see screenshot below), please open the phone and click on the Trust button that should appear on the main screen.  If the (untrusted) tag hasn’t disappeared after that, just unplug and replug the phone into the computer.  That should get rid of the (untrusted) tag.  If you try to build an app onto an “untrusted” device, you’ll get an error message reminding you to do the steps above.

When you’re done, the screen should look like the screenshot below; ResetTransmitter on the left, your phone’s name on the right, and no red error messages under the signing team area.  If your screen looks correct, then go ahead and press the build/play button.

Depending on if this is the first time you’ve built on Xcode, you may get prompts for codesign access and keychain access.  If those prompts appear, please enter your computer’s password and click on the always allow button to confirm.

Also, if this is your first time building with this developer account onto your iPhone, you may get another warning that the app could not launch because an issue with trust on your Developer Account on your phone.

Follow the directions on the warning.  Open your iPhone Settings >> General >> Device Management and then select your Developer App certificate and trust it.

Once you click the Trust on your iPhone, go back to Xcode, click on the blue OK button for the warning and then press the build/play button one more time.  This will finish the build of the app onto your phone.  Success!  You can unplug your phone from the computer and use the app now.



If your app did not build correctly and you got a “Build Failed” message and some red error message about “LoopKit” not being found…here’s the solution.

  1. Open Terminal app again (remember, you opened it before to install Homebrew earlier in the directions).
  2. Copy & paste this command into the screen: cd downloads/cgmblekit-dev && carthage update  and then press return.
  3. Wait for the command to finish running. Might take about 5-10 minutes, and then you’ll be returned to a blank line beginning with a $. You’re all done with Terminal app, you can close out.
  4. Now go back and try build button again in Xcode.



Special note for Loop users: Remove your Dexcom from Loop settings during the reset process described below. Only add your CGM source back in Loop settings after the reset is completed. Including all the way through re-pairing the reset transmitter back in Dexcom app and getting CGM data in Dexcom app. Once Dexcom is all happy and working again, then add the info back into Loop settings.

There are some warning messages in there about the use of this app.  One known impact of using reset transmitters is that you will have gaps in CGM data in your Clarity account. Most users see about 10-30% of their CGM data making it into Clarity on a reset transmitter…so be aware that your Clarity statistics may be spotty. Share accounts (follow and users) appear unaffected at this point in time. After resetting a transmitter, you can use the transmitter on a Dexcom app for replaced battery transmitters as well.

You cannot reset a transmitter that is currently in a session and/or paired with Dexcom or Spike, or any other device/app.  So, stop any currently running sessions, and quit the Dexcom app.   Forget the transmitter from your iPhone’s bluetooth list.  Forget all Dexcom transmitters from the list…no reason to keep old ones that you aren’t using anymore anyways. Re-open the ResetTransmitter app, enter your Transmitter ID and press the red Reset button.  Within 5 minutes you should get a pairing request.

If you do not get a pairing request and instead see a message “Unable to parse auth challenge: timeout” that means your transmitter is still busy with another app.  Double-click the iPhone’s home button and scroll through the open apps.  Upswipe on the Dexcom and the Reset apps to close them.  Restart the phone, re-open the Reset app, enter in the transmitter ID again and press the red Reset button again.  Within 5 min you should now see a pairing request.

If you STILL don’t see a pairing request, some users have reported that turning off Dexcom’s cell data within the iPhone Settings >> Dexcom G5 app can also help release the transmitter from Dexcom app’s influence.  If that fails…you can try deleting the Dexcom app and reinstalling it at the end of the reset process.

If you still don’t get a pairing request, make sure the transmitter is within pairing range of the iPhone (but not in active session).  The Reset app needs the transmitter close enough to be able to pair with it in order to reset the clock.

Once you press the pairing request, the reset command is immediately issued and you should get a confirmation screen like below:

You can now close the Reset app (double-click phone’s home button and upswipe Reset app) and forget the transmitter in the iPhone’s bt list again.  Reopen your Dexcom app and you’ll be able to use your transmitter for another 112 days or until the battery gives out…whichever comes first.

The free developer account that you signed the Reset app with only allows the app to be used for 7 days.  After 7 days, the app will simply produce a quick white screen and self-close if you try to open it.  You can rebuild the app anytime after the 7 days to use it again.  Simply double-click on the file in your CGMBLEKit folder download to open the project in Xcode again, plug in your iPhone, and press the build/play button.  All your previous changes will have been saved, so the rebuild is quite easy.

You can reset any amount of transmitters.  The app does not know transmitter ownership, nor does it have a limit on how many times you can use the app to reset transmitters.

The transmitter does not have to be on a sensor in order to be reset, just needs to have battery life left and not be paired already with another app.

107 thoughts on “Reset G5/G6 Transmitters”

  1. Question??

    What kind of warning do you get after reset before battery dies if any? Wondering if you get a warning so you can get another transmitter ready to go.


    1. You’d get the same warning as before a battery reset had happened…the transmitter has a low battery warning coded into it, but because of dexcom’s artifical kill-date, you just normally don’t see it. If it’s anything like the G4, it is not much of a warning…but at least a little bit.

    1. I do believe that x-drip may have added that feature? But otherwise, nope…all the options are in the Apple/mac arena for resetting

  2. Thanks so much for developing and blogging about this this Katie! Just a quick question… do you know if Dexcom accuracy is affected by doing this? I’ve had amazingly accurate readings on Dexcom for just over three months, but since resetting the transmitter clock the readings from my sensor are between 15% and 20% different to the readings from my BG meter. It might just be a ‘bad’ sensor and nothing to do with the transmitter clock reset but just thought I’d ask.

    1. Transmitter clock wouldn’t affect the sensor readings/discrepencies…probably a sensor issue unfortunately.

      1. I’m having the same problem. Since the reset the last two sensors have been consistently +/-3mmol/L in error, even when calibrating three or four times daily, which is a problem I’ve never encountered in the last 2.5 years of using the G5. My clarity and diasend uploads have also been affected, with most of the data missing and only a few readings per day coming through. I’ll put in a new transmitter and let you know if anything changes.

        1. My clarity reports are also showing only about 10 readings per day since the reset. It’s been 2 days so far. Did you find a solution?

          Katiedis are you hearing about/seeing this issue?

    1. The transmitters are hard to drop a pairing from one app over to the other. Deleting the dexcom transmitter(s) from the BT list on the phone, restarting the phone, and then opening the app that you want to pair with…that’s the best troubleshooting for when it won’t pair within first 5 min.

  3. Has anyone tried to reset it with an ipad instead of with a computer? I don’t have an apple computer

    1. you’d still need an apple computer to build the app, even onto an iPad. If you have an iphone though, and no mac…you can find the Spike-app and do it through that. The spike app has the reset built in as an option instead.

  4. Hi – Thanks so much for publishing this code. My daughter’s last G5 transmitter just died and we’re waiting for insurance to clear the G6. I followed the instructions and the build succeeded, but I don’t see an app on the iPhone. It was plugged into the Mac and I didn’t see any errors like you mentioned in the instructions. Any thoughts on what to look for?

    1. Yup, if you can find me on FB, i’d be happy to walk you through a fix. I’d need to see a couple screen shots to know where the problem is.

        1. The issue is that you likely do not have the ResetTransmitter app selected to the left of where you selected your iPhone from the list of devices (near the top of the Xcode window). You need it to say ResetTransmitter, like the screenshots show.

        2. In particular, look at my screenshot that has the build/play button circled and pointed to…look just to the left of the circled build/play button on the screenshot and you’ll see the word ResetTransmitter. You need to get that selected correctly before you press build/play button…or you’ll get no app installed.

  5. This sounds awesome, but I had a question. I’m an Android user. I have read through the entire process. My super close friend has an IPhone and my other friend had a Mac that they will let me borrow in order to build this. After the reset, will I be able to use the transmitter on my android with the dexcom app? Also, I’m fairly Apple product illiterate…lol. Is the AppleID going to be an issue since neither the Mac nor phone is under my ID not the same ID? I was assuming AppleID was similar to a Google account where I could just sign into my friends computer using my Apple ID and sign into the phone using my ID and it would be okay? Please Help!

    1. Yes, you will still be able to use the transmitter on your android device after using this resetTransmitter app. Apple ID is not an issue…that is basically just (any) email address that Apple “knows” you by. So, you’d want to create your own Apple ID if you don’t already have one (that’s super easy). If you already have one, you just use your own Apple ID on the friend’s Mac when you get to the step for “adding your apple ID in Xcode preferences”. The Apple ID is only used by Xcode when you enter it there. And after the build, you can delete the apple ID from Xcode preferences if you don’t want it hanging out on someone else’s computer. The app will still remain on your phone (7 days if a free account…a year or more if you maintain a paid developer account) even after your clear your Apple ID from their Mac.

      And technically there are third-party BG (non-dexcom) apps that have the reset feature built into the apps now (like spike and xdrip+). I don’t use those though because I much prefer Dexcom’s app and algorithm for how it processes the raw data, calibrations, and outliers…but that’s a different subject. And I’m not intending to write guides on those apps, as I don’t use them myself. But, they are out there.

  6. Samena Collins:

    You may want to look into using xDrip+ with Android, since it will ignore the Dexcom time limit and keep reading the values. Also it will report “Transmitter Days” which will account for all the battery life used so far, and give you a good idea of how much longer the battery may last. It’s free.

    Otherwise, the process done here is likely to work with your Android version of the Dexcom app; However if it does not, it may NOT be from within this process; rather it may be from Dexcom servers remembering the serial number and continuing to report the phantom battery status–since you will have to sign it in with Dexcom on the Android app (for first use?–this may not be the case, see below).

    The iPhone code used here may be used to bypass this –but as already obviously known, the Mac and iPhone are working together to make it happen. The serial number on the iPhone was or is already being used at the time of the “false” report of a dead battery. In theory, the transmitter would go back to working on the same registration from Dexcom.

    Hope that helps,

  7. In my case I had to do an additional step of selecting Product->Scheme->ResetTransmitter to get the build/install process to work.

    1. that is shown on one of the screenshots, you just must have missed that step. Others have missed it too. 😉 I’ll revise the post to try to emphasize that step so people don’t miss it. Thanks

    1. G4 transmitters don’t have an artificial cutoff like the G5 transmitters do…the G4 transmitters already go until the battery dies a natural death. So, you don’t need this for G4.

  8. Thank you so much! It worked perfectly and will hold me over until I get my G6 next week. What a relief! This is fantastic of you 🙂
    Thanks again!

  9. How would those of us WITHOUT ANY APPLE products be able to accomplish the same thing???

    The Dexcom Transmitter FORCED SHUT-DOWN is the #1 reason I stayed with my Dexcom G4…

    Well, that and my tSlim G4 pump isn’t G5 compatible…

    But when Tandem released their X2 pump and offered an “upgrade” option, I didn’t DOWNGRADE to X2 because Dexcom G5 wasn’t yet released and Tandem’s X2 pump wasn’t compatible with Dexcom G4!!!

    1. You’d have to look at android solutions…i’m not super familiar with those options. You could try x-drip+

  10. So I’m trying to follow your instructions (which are SUPER helpful btw!!!) but for some reason even though my iphone is plugged into my computer, it won’t create a provisioning profile for me to do the signing with, any tips? thanks so much for making this btw!!!!

    1. Did you add your apple ID account to the Xcode preferences? That’s how a provisioning profile is created for a signing team…first you have to create a developer account by adding one in Xcode preferences.

      1. I did and it comes up as my name followed by (personal team), but then it says there is no devices registered and failed to create a provisioning profile

        1. Ah, and there is a button beneath the “no devices registered” button that will allow you to register your phone. Look for the “Register Device” button in the signing team/provisioning profile area.

          1. I cannot get the “Register device screen, and although my iPhone 6 plus is plugged into the MacBookPro w/USB-C ports, I can’t see my phone. Please advise. I finally had to open my next G5 transmitter, as I couldn’t get this wo work. 🙁 But I do want to continue to work on it for next time. Thx!

          2. There’s no option for me to register my device. I created a Provisioning Profile with my Apple ID and my phone is connected to my Mac. Help!

          3. Hi, sorry to bother you! I cannot get a provisioning profile, and the button “Register device” does not appear, only “try again”. After some time now hitting the try again button it says “Your maximum App ID limit has been reached. You may create up to 10 App IDs every 7 days.” It also says “Xcode couldn’t find any iOS App Development provisioning profiles matching ‘com.MyName.ResetTransmitter’.” Any help would be greatly appreciated!

          4. First, a big thanks to Katie for this awesome article. The ability to “Register Device” under the Signing/Status tab in Xcode has, from my understanding, been removed since this article was first published. The function of Registering a Device within Xcode (with simply a free Apple ID) is no longer possible.

            However, if you register as an Apple developer (, you can sync your developer account to your iPhone. The only downfall is that to gain the opportunity to be a developer, Apple charges $99.00 per year. From my understanding, this is now the only way to sync your apple account with a UDID/your Iphone.

            The good news is that if you are (or pay to be) an Apple developer, you can sync your device and the process will work perfectly as described by Katie’s article.

            The take-away is, there is no longer an option to register a device within Xcode. Hopefully this helps.

          5. @katiedis – There is no “Register Device” button, as the other users have pointed out. MBP Late 2016 + Mohave (10.14.1) + Xcode 10.1 + iPhone 6s + iOS 12.1.

            After selecting my team, it thinks for a moment and then shows:


            Status: Failed to create provisioning profile.
            There are no devices registered in your account on the developer website. Plug in and select a device to have Xcode register it.

            ==> Try Again button <==

            No profiles for 'org.fister.ResetTransmitter' were found
            Xcode couldn't find any iOS App Development provisioning profiles matching 'org.fister.ResetTransmitter'.

    2. Shannon, Rachel, Casey, Kristine,

      I had the exact same issues and figured it out. I was getting those same error messages for the longest time. I actually ended up just not worrying about it and proceeding to the next instruction Katie provided, even though I still had 2 red error messages. After completing the following step (see below) – those error messages went away and things worked perfectly. Hope this helps!

      “Now, navigate up to the top of your window and select two things; one from the left side of the box you’re going to select ResetTransmitter and from the pop-out, you’re going to select your phone’s name from the very top of the device list (not just your phone model…you want to go all the way to the top of the list for your phone’s name).”

      Additionally, if your phone isn’t showing up as your phone, try clicking WINDOW -> DEVICES AND SIMULATORS -> and then unlock your phone. This should prompt you to add your iPhone.

      Lastly, Katie, whoever you are (I just randomly Googled to try and fix this) …THANK YOU. I’m currently traveling in the Middle East and my transmitter battery showed low. I wasn’t able to successfully stick on a new sensor bc my iPhone wouldn’t accept my low battery transmitter. I was kinda freaking out. This saved me big time until I get back to the states. Thanks!

  11. First, thank you from the bottom of my heart for developing this app and sharing it. It has been a life saver. Second, it took me two downloads of Xcode on 2 seperate computers and 3 trys before I got it right. I think it had a little to do with the directions not sequencing well. Very minor things like FIRST delete all Dex apps from phone and computer, etc. Anyway, they were clear enough for me to get it after a small amount of frustration. Again, thank you and bless you.

    1. But, you don’t have to delete the dexcom apps from phone or computer. 😉 Depending on the computer you have, true…some older ones can’t be upgraded to the newer macOS software (High Sierra) in order to build this…so some people may have to borrow a friend’s newer mac. And, getting the transmitter’s bt pairing to leave Dexcom app is very much a step-by-step process (I did write them up in here)…but deleting the dexcom apps just allows you to be a little quicker with the unpairing…but deleting dexcom apps doesn’t need to be done. Just an FYI. Regardless, glad to hear you had success!

  12. Hello,
    Can I pay someone to restart my son’s G5 transmitter? Yes, I know you’ve given a very nice DIY set of instructions, but I’m not confident I can do it correctly. Can I send you or someone a G5 transmitter with a replaced batter (done by Tech Guruz) and get back from you a transmitter that will work again? If so, how much $ ?

  13. Thanks! All worked as expected! For me it took extra 10 minutes to figure out that bluetooth on iphone was off and that’s why it wasn’t looking for transmitter, but after that – all worked great!

  14. Thank you so very much for these fantastic instructions! I was successful in getting the reset app onto my iPhone as well as resetting the transmitter. I deleted all from the bluetooth list however when i open the dexcom app and try to pair the transmitter to the app it does not find it. can you offer any suggestions?
    Thanks again!

  15. Thank you so much for the post! I switched my insurance carrier & instead of sending me two transmitters to last 6 months, they now send me ONE transmitter every 3 months. So instead of having a backup Xmitter part time, I now have no backup.

    I asked the rep what I’m supposed to do if it stops working, since I have no backup. I was told to call Dexcom, who could ship a replacement overnight. I asked her, “What if I’m overseas and out of country?”. She said I have 2 options: Buy a backup for $650 USD or simply switch to fingerstick testing until you get back.”

    I’m so glad there’s another option. This company has us over the barrel…and they know it. Makes me livid!

  16. I’m having the same issue. There is not button for “Register Device” and my phone is plugged into my computer. I tried to post a screenshot of my screen but I can’t figure out how to do that either.

    1. may have to make sure you accept the “trust” this computer pop-up on your phone. And make sure your phone is not locked or passcode locked

  17. Wow!! Great work. Thank you. Took me a couple tries, but the app is on my phone!

    Question: I currently have an “extra” G5 transmitter sitting on my desk (replaced due to some funky issues). I suspect it’s still good, but may time out very soon.

    Can I use the Reset app to reset this “extra” transmitter without needing to terminate my current session by deleting my transmitter from the BT list? I hate to have to restart the current sensor.

    This would let me set up an emergency backup transmitter ahead of time.

    1. Yes, you can restart a transmitter that is sitting on a desk. Doesn’t matter that another transmitter is currently going on the phone…just so long as the transmitter you want to reset isn’t in a session

  18. My build was successful and I have the app on my phone. However, I have tried 3 transmitters and cannot get any of them to reset. I just get a spinning wheel and never a pairing request. I have done all the steps to remove old transmitters from BT. I even set up the app on my own phone (not my son’s who uses Dexcom) and am trying to reset a transmitter at work, far away from any BT this transmitter would have been associated with. Any thoughts on why I never get a pairing request? I think I should have battery life left on these.

    1. You can always use a free BLE scanning app to check and see if the transmitter has battery life left. If the transmitter still has battery left…the scanner will pick up its signal. Leave the scanner app open for a minimum of 6 minutes (the transmitter only sends out a signal every 5 minutes) and look for DexcomAB (where AB are the last two digits of the dexcom transmitter’s ID).

    2. you can use a free BLE scanner and scan for 5 minutes to see if the transmitter sends a signal. That’s a good check of battery life.

  19. Dexcom currently has a 10-day shipping delay on G5 transmitters. This post was a lifesaver!

    I’m a diabetes supply hoarder and the lack of back-up transmitter has always bugged me. Hopefully over a few cycles, this will enable me to get a back-up. Of course, that will be just in time to upgrade to the G6!

      1. I have neither hypo nor hyper awareness. I’ve (apparently?) hosted business meetings at 20 and been unaware of 500’s. My CGM keeps me alive. I’m single and travel routinely. Each and every time I’m denied it, my life is at risk.

        I’ve been a T1 for 43 years; 55 years old. No major complications to date (bit of microalbumin in urine). I’m exceedingly blessed to be a comfortable, over educated person that has the opportunity to spend the time needed on these sorts of things. I can’t imagine how anyone does this without the leisure to have a fight now and then.

        This feeds into the other post of yours – “Why do I restart?” With the G5 transmitter timing out every 90-100 days, I routinely went 1-2 weeks without one. No one realistically accounts for how long the turn around is. I’m lucky if I reorder at 85 days (earliest OptumRx will let me) to get one by 105 days.

        This cycle, I ordered replacement transmitter at 85 days. Needed new prescription, so that took a few days. OptumRx told me a week later that they were out of stock and had no timeline to get G5 transmitters again. So they said they were going to start the process for a G6. Ok, that means a few weeks without a CGM and lots of wasted sensors, but go ahead?

        Another person from OptumRx called me three days later to tell me that I was only 11 months in on the G5, so couldn’t have a G6.

        So I called Dexcom, and they said I could cash pay $600 (my insurance won’t let me deal with Dexcom directly) and they would guarantee shipment in 10 days. Asked about their plans to provide 3rd party suppliers and was sent in circles. Told OptumRx that Dexcom would ship in 10 days, they said that wasn’t their understanding.

        I don’t like paying a company $600 cause they can’t manage their own supply chain. I will likely do it and, with restarts, use up my G5 supplies while I stockpile G6 stuff that is eventually covered by insurance.

  20. Katie, thank you for this post!!!
    I restarted g5 transmitter about a month before it’s programmed shutoff (we were away for a month and I was afraid it stops before I have access to a computer). It worked well. However, after a full month (and about the time of its programmed shutoff) I got a sensor failure and within minutes transmitter failure. Had to pair a new transmitter. Can you think of the reasons why that happen? Why the transmitter did not last past the 112 days even though it was restarted. Thank you!!

  21. Thank you so much. Our CGM vendor and the insurance company must be looking for my authorization with the Mars rover using pager technology from the 90s while on a dingy in the middle of the Bermuda Triangle. Or at least thats how it seems because they act like it is a Very Systematic Approach to confirm that I am eligible to receive the supplies that we have been receiving for years. Meanwhile, we are paying about $800/month in insurance and my daughter is starting kindergarten with a very planned out care plan that includes the use of a CGM and our CGM just timed out. Well, thanks to your work, we now have a transmitter that will likely hold us over until the Nasa, or the powers that be, approve our order. Like some of the others that were receiving errors. I tried erasing and re-downloading the code file and I think maybe don’t hit enter in the General/Reset Transmitter tab. Just change the name per the instruction and select the team then select your phone and hit run once everything looks right. I had all the later errors come up and I had to trust it on my phone etc. Also, when the transmitter starts to pair with this app, you need to hit pair quickly or it times out and you need to forget the cgm bluetooth device and try again in the app.

  22. Just wanted to weigh in here – I reset a battery a month ago, but was unsuccessful to get it to work again yesterday. However, I reset a different one and WAS able to get it to work again. Wonder how long it’ll hang in there?! Pretty cool stuff.

    I have a few questions, but I’m going to reread the thread to see if they were addressed already.

  23. Hi, do you by chance know whether it is possible to see / find out when and which transmitter was in use in the past? I have recently 3 of them and didn’t mark when each of them has been inserted (and “died”). And would like to try to reset the oldest one first :-).

  24. I’ve reset both a G5 and G6 with this method and they’ve both worked to restart the transmitter, but both times I’m not able to get data into Clarity. In the post above you mentioned that there haven’t been any issues noticed with it. Any idea how I can get my data back into Clarity as I do use that a fair bit for analysis. Thanks!

  25. Hi Katie,
    Love your work on this page and thank you for doing so. I built and used the G5 Reset app last night. Did it in a hurry as was under time constraints so I couldn’t read and digest all instructions as I would usually do. That is to say, I didn’t procrastinate!
    I have an Apple Developer account as I am using ‘Loop’ on my iPhone so the install instructions may have gone a little differently ie I didn’t need to ‘Trust’ my phone as I’ve already using Xcode for Loop & didn’t need to search for the DexcomQD in BT settings. I had removed the DexcomQD before doing the reset and had also closed down the Dex App and my Loop app.
    Afte doing the Reset which completed as prescribed I tried then to Re-pair my G5 Txmr, and it failed. I have tried to Re-pair the Txmr several times now and Dex App shows Transmitter Not Found. Using a BLE Scanner I have seen the DexcomQD device in Bluetooth but does disappear. I have rebooted my phone. I have deleted and reloaded Dex App. Still no good. I did get 106 days out of the Txmr but this is less than what is to be expected. Haven’t used Spike either but may be my next step if I can’t get Dex App running with reset Txmr.
    Do you have any tips that might help me reconnect this G5 Txmr?

  26. Hi Katie, thanks so much for this! I followed all instructions and reset the transmitter successfully. Unfortunately, now I’m getting a “Transmitter not found” error message. Even on my t:slim X2 it is saying that the Transmitter ID is invalid. Any thoughts on this?

  27. Hello Katie,
    Your work on this is fabulous. I am incredibly grateful. I am now on week 4 of my second transmitter session and going strong. The problem I incurred today was when I tried to use option 1 of the restart sensor. The receiver asked for a new transmitter and would not accept my old transmitter ID. How do I handle the receiver portion of the transmitter restart?

  28. Just wanted to say thank you so much for these instructions. I had a G6 sensor fail on startup yesterday and as I’d just had the ‘transmitter expires in 2 weeks’ message I decided to take the risk and reset the transmitter to try and get the sensor (which is my last one) to work. I got a bit stuck in Xcode (having never used it before) but eventually got it to work and hurrah – my transmitter reset and the sensor is working! Thank you.

  29. Just wanted to say thank you so much for these instructions. I had a G6 sensor fail on startup yesterday and as I’d just had the ‘transmitter expires in 2 weeks’ message I decided to take the risk and reset the transmitter to try and get the sensor (which is my last one) to work. I got a bit stuck in Xcode (having never used it before) but eventually got it to work and hurrah – my transmitter reset and the sensor is working! Thank you.

  30. Thank you so much!!!! We are waiting for insurance to approve things and the transmitter died tonight. I wouldn’t have felt comfortable sending my son to preschool tomorrow without it. I have a whole stack of other transmitters too so I’m interested to see if any of them still work!

  31. Hi Katie,

    Thanks so much for figuring this out! I was able to reset my transmitter which I’m really happy about given the costs.

    Since I did my reset about 5 days ago the data as viewed in my Clarity reports is missing out of the readings. Have you seen this? I’m happy to provide a screen shot, but essentially what is happening is that 4-5 times a day it shows about 1-2 hours worth of data, but the rest of the day is blank.

    Not sure there’s much to be done about it. It seems there is some data that is being included or omitted during the reset that is causing this down-the-road side effect. If I can help you in any troubleshoot this by being a tester (or whatever) I’m happy to do it.

  32. Katie,
    Thank you for all you have done for us.
    I followed your instructions and successfully restarted my G6. However, when I went to restart my next sensor session, the receiver would not allow it, insisting on a new transmitter. Have you figured out a way to trick the receiver to allow and transmitter restart?

  33. I am getting the following Status remarks with a “Try Again” button that does not resolve the problem. ” I have an iPhone 6 Plus. Failed to create provisioning profile.
    There are no devices registered in your account on the developer website. Plug in and select a device to have Xcode register it.

    No profiles for ‘com.robinhansen.ResetTransmitter’ were found
    Xcode couldn’t find any iOS App Development provisioning profiles matching ‘com.robinhansen.ResetTransmitter’.”

  34. Katie,
    I want to thank you for all your work and explanations.
    This was one of the most detailed step by step code walkthroughs I have seen.
    I have the updated RESET XMTR app on my iPhone ready for my Transmitter to go dead later this month.

    I assume I wait for it to go dead first then reset it?

    Hopefully, this might extend it a few months or so. If this works when we go on out of the country for a half year
    I will be short a transmitter while I am gone.
    so This may extend the one I take with me.
    I will not be getting any sensors or transmitter while I am out of the country.
    I used to code and program computers on the ground, in the air and in space starting in the 1960’s and later went on to work on the Moon landings and manned space flight and eventually became Chief Scientist.
    Thanks for all your time and detailed work on something that will help a lot of people.

  35. Thank you, this is great. Question – what about the Receiver (we use that in tandem with an iPhone? That seemed to still be running during this process. Do we stop the sensor on the Receiver as well?

  36. Help! I’ve gotten to the part about

    But then I get these error messages after selecting my team (after selecting a replacement name for loop kit):

    The operation couldn’t be completed. (OSStatus error 100002.)

    No profiles for ‘com.seamus.ResetTransmitter’ were found
    Xcode couldn’t find any iOS App Development provisioning profiles matching ‘com.seamus.ResetTransmitter’

    what have I done wrong?

  37. We went through all the steps, when we attempted to build the app we got 2 errors, not sure what to do to fix it, is it possible because we are running Mojave OS instead of high sierra?

  38. I too want to thank you for the great and clear instructions. Breath of fresh air.

    Wanted to note I had to install something called “carthage” to get this to build. Used homebrew to get it installed.

  39. Greetings – when I hit the build, I am getting three errors now-
    Validate Project Settings – unable to recommend settings

    a cart file issue
    -unacatagorized command phasescriptexecution failed with a nonzero exit code

    cgmblekit 1 issue
    Swift complier error – no such module ‘loop kit’

    I thought I followed all of the above instructions completely. I have a screenshot of the errors as well. Everything is updated also. Anyhelp would be appreciated.

    1. Hey Brian,
      Did you ever get any response to your Swift complier error issues? I’m having the same, thinking it’s because I’m running Xcode 10.3 with OS Mojave but also may just be that I’m a tech caveman.

      I’ll keep looking for help around and let you know if I see any, I’d welcome anything you figured out too…


  40. I have successfully reset the g5 transmitter but now I can’t get it to connect with the phone keeps coming up with transmitter not found.
    I have tried several times deleting app and forgetting the Bluetooth and resetting the transmitter again but no luck
    Any suggestions

  41. When is the last time anyone was successful with this? My success has been very limited, despite trying off and on for several months.

    Just wondered if there were any coding updates needed.

  42. Hey Katie!

    Not sure what I’m doing incorrectly, but my build failed.

    The personal word I used was an error, as well as this message:
    Command PhaseScriptExecution failed with a nonzero exit code

    Is there anyway I can still reset this?

    (Also, this whole thing is brilliant. Thank you!)

  43. Hi. I just followed these steps but am getting error messages. Do you have any updated instructions for the newer mac os?

  44. Thank you so much for this info!
    We finally were able to make it work, but the link to the software above downloaded the latest version (3.0), which DID NOT build (kept getting an error). Because we were using Mojave with Xcode 10.2, we weren’t sure if the OS or new Xcode were the problem. So, tried other versions to no avail. Fortunately (after much searching), we found the github site for the previous release of 2.1.1 (, which worked flawlessly on Mojave/Xcode 10.2. So anyone else needing this fix, you should use the version linked in this comment.

  45. Why doesn’t someone just make this app available for everyone to dl and use instead of going through all this rigamaroll every time you want to reset a transmitter?

  46. I followed the instructions for building the app but I can not download Xcode. Do I need a paid Developer account? In the app store the download button remains grey.

    1. Sounds like more of an issue with you not being signed into the App Store with an Apple ID. Try checking to see if you are signed in and that your computer has enough free memory to download Xcode.

  47. Thank you. This will be nice to have in an emergency. Sorry if I missed it in the write up, but how much extra time people typically get out of a reset transmitter?

    1. It will vary, but TOTAL age of a transmitter is usually around 180-200 working days before the batteries die.

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