Dexcom G6 Sensor Failures

I’ve neverv had a sensor failure for any of my dexcom g6 sensors. I was on the g5 for the first 90 days, and since then I’ve gone through nearly 20 sensors and every one worked perfectly.

With the g5 I used Spike, which I sideloaded to my iPhone, and was always able to get the full 7 days out of the sensors, and more. I estimate I was getting 10-11 days on average for each. I got over 110 days from my transmitter, and that was the component that so think actually failed in the end.

I occasionally had issues with the g5. I’d get the ??? Saying there was perhaps acetaminophen or some other problem, and it would either fix itself, or I’d have to change the sensor. Also, I think I had two insertion failures from not pulling the collar back correctly. And the needle was much more painful than the g6.

After approx 4 months of using the g5, I switched to the g6. I always place it on my abdomen. I use IV prep wipes to remove oils and anything else from my skin before inserting. I simply peel the backing off the bottom and putting it down careful placing the adhesive onto my skin. Break the orange safety piece and push the button. Hurts less than the g5. Go around the adhesive with your finger. Heat helps activate the adhesive. Then just place the transmitter into the sensor. I always use a regular alcohol wipe on my sensor right before inserting.

To start, I use my Tandem t;slim x2. I start the sensor and enter the 4 digit code for auto mode. After a few minutes, my phone will sync and show it warming up and showing time left. Don’t start on multiple devices. To ensure I have no issues with my adhesive, I use a Simpatch, I bought from Amazon. All sensors have lasted the full 10 days. I use unisolve adhesive removers to remove it, which smells like acetone.

Some people report frequent failures and I don’t get it. In auto mode, I need no finger sticks, and it just works. Sometimes I have issues with the Bluetooth on my iPhone, but usually I can get it working again.

I’m not sure why some people are having lots of errors and I’m having none. I am on Medicare, and the box says Medicare/Medicaid DME only. I figured they were giving us lower quality sensors, but everything seems fine here. I just keep wondering why people are having so many failures.

I have found with the last shipment of sensors (I order them in 90 day supply) that my sensors have been working well until I get to around day 8. What will happen is that the sensor will lose connection for up to 2 hours and then reconnect.

I have been on the dexcom g6 for almost two years but i started with the g5. In the last couple of months i have had my sensors working so well to day ten. But a few months ago i also noticed the same pattern around day 7 or 8 i would start getting sensor errors and it would go in and out all day long and when it did come back online it was over 50+ points off. We did end up calling Dexcom and i have noticed since January that the sensors have been working to day ten. Atleast for me anyways. Hope this helps!

I’m having similar issues with the G6 longevity. Lately most of them are accurate for about 6 or 7 days and then I’ll get erroneous readings. It’ll be off 50 or 60 points. Then it’ll go in a “calibration error” loop where it keeps asking to enter a new blood sugar reading every 15 to 20 minutes. Just this week, I was in this loop for about 6 hours and decided to change it. I had it on for 5 days. Haven’t been able to get in contact with Dexcom (COVID19) and submitted two (2) inquiries through their website. Once on 3/20 and the other on 3/23. I’m on Medicare and have used up my entire monthly allotment (3). Hope this situations improves soon.

It is interesting to see that others are experiencing almost exactly what we are going through. Recent batches of G6 sensors are failing short of 10 days. This seems to fall into 2 categories. The ones that lose accuracy, or act flaky, around day 8 to 9, and those that are now failing at 4 to 5 days. My son has been using Dexcom sensors for about 4 years, first the G5 and for the last 12+ months the G6. The quality seems to go in streaks. We have had boxes of 3 that last the full 10 days, and boxes of 3 that fail at any interval. For the last 3+ months, none have gone 10 days. We are very careful on how these are inserted in the fatty area on my son’s abdomen and the site is thoroughly cleaned prior to insertion (as is the transmitter). We have no issues with the sensor remaining attached to his body. Especially with Covid he has not been particularly active (sadly). I watched the last one fail as he was sitting stationary and studying for school. Some may not know this but the sensors will fail early if blood sugars are continually high, or if a calibration differs greatly from what the sensor is reading. If continually high it will wear the sensor out prior to the 10 days. However in Dec 2019 we were fortunate to be able to upgrade to the Tandem T-slim pump which has its control IQ technology (integrates with Dexcom G6). It has done a great job of increasing time in range so lately, more than previous times my son’s BG is in range and not high. This makes the more frequent sensor failure all that much more puzzling. We have a lot of experience with these sensors, treat them with respect, but are having an increasingly difficult time with them. We love the integration between the Dexcom sensor and the Tandem T-Slim so are not likely to switch to another sensor (the new Tandem technology is just too good) The Dexcom sensors are very expensive when we have to purchase extra sensors out of pocket because they are not lasting.

Are you saying that Dexcom won’t replace your sensors that fail early?

for the last several months my dexcom G6 sensors have been failing after 5+ days. Rarely making it to the 10 day final.

Hello all. I believe Dexcom is supposed to replace your G6 sensors if they don’t last the entire 10 days. I’ve only had one problem with the G6, but as with the G5 if I had an issue I cake Tech Support. It will probably take longer to reach someone due to COVID, and when you do you’ll be subjected to a barrage of questions. I’ve found they are checking that I went through the proper steps for insertion, and an using an approved site, etc. While I wear mine on my upper arm from time to time I’m told they may not replace one inserted there because that area is not approved so you may want to check that for yourself.
If you can, keep the box with the lot number or make a note of it, because sometimes there is a production problem.
I’ve always had a replacement sensor overnighted to me. So rather than go without, or buying out of pocket, contact Tech Support first.

G6 sensor issues for those using a t-Slim as primary receiver, i.e. all using CIQ, should make initial report and claim for replacement directly to Tandem.
This does not apply to any G5 matters.

Wait times for technical support are relatively short no longer than pre-corona days.

I find my G6 sensors tend to go a little wonky on day 8 or 9. Maybe the location of your sensor is causing it to struggle with finding your real number. It is so frustrating when you need to see your readings and it says sensor error!

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@lilsprogis Welcome, Lilly, to the JDRF TypeOneNation Forum!
Thank you for posting, all thoughts and diabetes experiences are welcome. I agree with the “frustration” you experience when a number and arrow isn’t present when meal-time comes about. At other times, I’m not too bothered because I can see the trending graph that stays on my pump and phone.

Just new to this site, reading different sections when I hit on your email. I have had very similar experience. New to Dexcom G6 this year. First 4-6 months very few sensor failures. Last few months, multiple sensor failures. Dexcom has always been very efficient in replacing sensors. But haven’t got answer as to why sensors are failing so frequently now. I had used alternative sites such as arm, so went back to just abdomen as they suggest, but still getting failures. Only other thing I am seeing is that if I get a big fluctuation, seems to start spiral down to failure of sensor. I had a breakfast meal and underestimated Carb content, so sugar shot up, overcorrected and went down and then got back to good level, but seemed to doom the sensor to loss of signal and eventual failure same day.

I contacted Dexcom and asked if they had changed manufacturing of sensors in any way since it seems to be a recent phenomenon, but rep I spoke with was unaware.

I see your note was from 12/19, long before I was signed up for this forum. Have you learned anything in last 9 months?

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Hi John @sublot37

I have not learned much new since the original post. Like some others I get about 8 days and then on day 8 I get wild readings and sensor errors. I usually calibrate 3-4 times on day 8 and then change the sensor on day 9. Since I don’t get a full 10 days I call Dexcom after a handful of early changes and complain and they send me a replacement.

I decided that 7 good days with only a few finger sticks is as good as it’s going to get. And that works for me.



I am doing the same. If fails early, request a new one. If gets close to 10, suck it up and move on. Given rapid drop in durability, wouldn’t surprise me if they changed manufacturing (something cheaper) in some way, and we are paying price. Or they are adding up money made with change vs money lost on replacements.

Thanks for note back. Best regards.


Well, my pump showed the sensor error code — again today. I had to replace a sensor after 7 days on Tues. Last night which was Friday, I had the — while eating supper. Readings came back in about 45 minutes and in another 15 minutes the arrows returned. Then today, Saturday, at lunchtime it did it again —. It is working right now. I have noticed that sometimes a big drop from a high blood sugar seems to cause the errors. This all started about 6 months ago. I am sitting here drinking water thinking that maybe I’m not taking in enough fluids and that is causing the sensor to malfunction. I just know that I always use my abdomen and maybe I need to try some “virgin” territory on the back of my arm. Just sick of it all!!!

Party @happyquilter, I emphasize with you. I’ve experienced several similar incidents over the past few months.

I o ly swap out the se sensor when it stays out for close to three hours. Like you, I have only used my abdomen, maybe I should also try my arms. I’m skinny, and try to stay well hydrated.

I have lost a lot of weight, so I am concerned that maybe I am TOO skinny now to wear the G6. My sensor just went out again a little while ago and now back in half an hour. I’m only on day 6, but it goes out every single day and went out twice yesterday afternoon. I love this thing when it works but causes me stress when it doesn’t.


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