G6 Review (using sensor code + calibrating)

So, last night at 4AM, the G5 transmitter battery died and I had no other transmitters (with functioning batteries) that I could use so it was time to pull out the G6 supplies. It was super easy to put on him (he loved it) and the real estate it takes up seems to be quite a bit less (elevation on the arm especially for the height of it.)

But what is ■■■■■■■ me off about it is that the accuracy isn’t there (as I expected it wouldn’t be since neither was the G5), but now it’s harder to CALIBRATE because the calibrate option is hidden away in a menu. It’s the 3rd time since this installing it onto him this morning that the numbers have been off by 50 or more. Also, about 30 minutes ago when I was changing his POD, his CGM read that he was 230 but after checking, I discovered he was only 130. So we calibrated in the G6 app and now for the past THREE ATTEMPTS at entering new BGs, it’s making us come back in 15 minutes to calibrate AGAIN…this is starting to ■■■■ me off.

I’m sure I’ll get questions of where did you put it…we put it on his arm - same place his G5 was for the past however many years he’s been wearing the G5. Upper butt, abdomen isn’t good for him - the arms is the spot he wants the CGM in.

This keeps happening (it’s the 4th time we’ve seen this error now since attempting to recalibrate it the first time.) Is this Dexcom’s way of chastizing me for informing it that it’s wrong?? How dare you challenge the mighty G6 numbers behind the curtain!!! Here, take this!


I can’t see how this would pertain in any way, but it’s one of the things I like to know when someone is having problems with the G6. Did you enter the “no calibration needed” sensor code when you started the sensor/transmitter?

I really don’t know what to suggest in these situations because my G6 is typically within 10-25 mg/dl of my meter. Some have talked about having problems within the first 24 hours, but frankly I’ve never experienced that either.

I also never “pre-soak” unless you count the 5 to 15 minutes that occurs because I insert the new sensor before I remove the old sensor so I can transfer the transmitter to the new sensor.

But then I also had good results over three different flavors of Medtronic CGM prior to switching to the G6. And people are almost willing to pay for any opportunity to hate on Medtronic CGM. :man_shrugging:

I hope someone else can suggest something that helps. :slightly_frowning_face:

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If that was an option, I didn’t see it so I guess no is the answer on my selection, but after the 2 hour warmup, there was NO calibration needed…the number just appeared at the end of 2 hours.

Update: If you are talking about the number that’s on the sticky tape of the injection gun yes, I entered that number.

Lots of “younger” patients (< 10) have reliability issues with the Dexcom G5 and G6. I’m one of about 10 I am aware of that I’ve helped at one time or another with various issues with their children. The CGM is great for me where “trending” is concerned, but when it’s reading really high or really low 9 times out of 10 it’s just wrong.

I never pre-soak either.

It eventually allowed us to enter a number that it accepted… 5 attempts later

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I’ve calibrated (finger sticks required, entering BGs required) more so far with the G6 in this one day than I normally do in 3 or 4 days with the G5’s. :laughing:


I have had much better luck not entering the code on startup, and instead just calibrating the crap out of it until it gets in line. :wink:

And on the waiting 15 minutes thing, yeah it’s stupid. But I figure, since it’s just showing me crap numbers anyway, who cares if I don’t see a reading on it for 15 minutes. If you are confident Liam’s BG is flat, you can just enter the same BG number you did last time.


When looping, it’s just a lot more numbers entering in numerous locations to “keep things working”. It’s annoying but hopefully it’s just beginner issues will get worked out over time.

Liam really loved the G6 insertion…he was like…what? Is it in? And I could see a big smile of satisfaction on his face that this is what it would feel like for him to get the G6 on.


I find the G6 goes to “sensor error” with too many calibrations and I try only to calibrate when the reading has been level at least 20 minutes. I also plan on extra fingersticks during the first and last 24 hours. I do “pre-soak” but only about 2 hours and that seems to help.


That wasn’t the case with us in this instance. It happened to me with the very first calibration. The CGM read 230, I did a finger stick to find out he was only 130, calibrated one time, then I dealt with 5 consecutuve “enter another number at this time” messages before it finally accepted one.

This is going to be very painful if it really requires something like this. I HATE letting the CGM just be wrong for so long.


Oh! In hindsight I assume that’s what your “Calibrate after 5:36 PM” screen short is about? :thinking:

I have definitely seen something like that error though I can’t remember the exact context or whether it was with a G6 or not. The CGM logic (for both Dexcom & Medtronic) tends to get really fidgety about a “large” calibration based on whatever its internal logic considers to be “large”. In your case I think you where attempting to calibrate from 230 down to 130, correct? That sounds like it would be enough for the G6 to run into problems processing the calibration.

I’m not sure what sort of help Dexcom cust support might provide, but, if you are up for it, you might try calling and ask them if there is a better way to cope with this sort of G6 calibration hesitancy problem.

Perhaps they might also have some suggestions/tricks for installing the sensor which may help mitigate the initial large errors you’re seeing. The support line can be hit or miss, but sometimes you can get lucky. :slightly_frowning_face:

Again, sorry I don’t have more to offer than the relatively obvious. :disappointed:


Could be a crap sensor. We have had runs of bad luck in regards to the sensors, then many many months where everything is ok. I hope this settles down for you quickly, since it is so central to looping, and man are you getting great results from that.


I tend to run into lousy sensors often. I do calibrate if its way off, but if it doesn’t stop being a pain by the second day, I’m done with it. And, really, Dexcom has been great recently whenever I report a faulty one. The last guy I talked to said to just take it off if its acting up, if you have some in reserve. I know that’s not a great solution, but its been the only solution for me.
Like @Chris, I find that I’ll have a few bad in a row, then smooth sailing.


We find the arm doesn’t work as well with G6, just FYI. We used to use arm for Samson with G5 ages ago, but have switched exclusively to tummy for G6.

The last sensor – which was 410+ points off – was a rare one we put on his arm after a series of early failures. Every 6 months or so I’ll get frustrated with the pain of insertion on the stomach and try it again elsewhere to see if we can get decent results, and it always ends up being a disaster.

Anyways, I hope that’s not the case for Liam but that’s what we have found. Samson has too little fat I think, for many places to be a decent option. May work better for Liam, we’ll see.

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Yep, now we don’t need to call. We just use their Tech Support form fill and enter every single sensor that fails before the end of the allotted period. They always ship replacements to us quickly. No need to wait on hold.

Also, we recently got approved for 7-day sensor replacement, and now only request replacements for sensors that fail before day 7. It winds up being a better deal for Dexcom too, as almost none of our sensors lasted the full 10 days.


I asked Liam is he would want to try him tummy and he flat out said “no”. Lol. I’ll keep trying.

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My son is older, but he won’t put the Dex anywhere else. He just likes it out of the way and of course it works better for him in the arm than your son.

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Does this mean your script / insurance now covers 4-5 sensors per month?. Do you force stop them after 7 days even if working?

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I have used dexcom web form too, although have recently called Tandem when related to some strange errors where pump said cgm error, but phone/xDrip was working fine. Tandem said the transmitter should be replaced too, and put order in for me.

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It does cover 4-5 sensors per month – I think this last shipment sent us 12 instead of 9. The sensors can go till 10 days; there’s nothing special about the ones they send me. But my experience is they almost always fail by day 7 anyways.

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Sounds like a similar problem may begin occurring in my house…


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Yep… So far NOT a fan…

It’s so easy, they said… No calibrations necessary, they said…