Dexcom reliability and Control IQ

Tandem Control IQ in conjunction with the Dexcom G6 is only as good as the reliability of the G6. If the G6 is way off (e.g. saying 60 one arrow straight down but the finger stick says 115), the CIQ will stop the basal until the G6 has figured itself out.
How do you deal with that? Lately the G6 has been pretty erratic for us and we’ve had to request replacements from Dexcom.

My daughter will end up going fairly high after a scenario like that.
Any suggestions?


I would suggest more frequent finger sticks and, of course, making sure that your tester is running correctly by comparing it with a test at your lab.

You do know that the CIQ can be calibrated. I don’t often have to do that but sometimes when the numbers are too far apart, one has to.

Isn’t it possible to turn off Control-IQ when the Dexcom G6 is erratic? That way you can fall back to the programmed pump settings and let your fingerstick readings guide your treatments. Have you been trained how to calculate corrections without C-IQ?

Unfortunately, no automated insulin dosing system is 100% accurate and dependable. It’s up to the user to monitor performance and switch to “manual” when necessary. As much as we’d all love to offload insulin dosing responsibilities to an electronic brain, the human brain must step in when necessary. Good luck!


Yes, and it will go to your personal profile. I will do a calibration of the G6 if it way off from a finger stick.

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Have you tried placing the sensor in different location? Abdomen gave me poor results but moving to the arm provided much better results.


Try using sensor from a different box, if several fail in a row.

Another option is to drink more fluids, especially now with warmer weather.

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Thank you all for your input. I agree that the sensors seem less unpredictable on my daughter’s arm. We do have more issues with belly placement. She’d rather I don’t put it on her left arm since that’s the side she sleeps on. But can I continually place it on her right arm?
Also, if I temporarily turn off CIQ, does the pump revert to its former programming (e.g. Sleep mode or regular mode) when it’s turned in again?

I assume I’m much larger than your daughter, so I don’t know how possible this is for her… I put Dex on the inner bicep. If the arm is flat against her side, it would be the last little bit of arm skin before it disappears into her side. That leaves just enough space for clear communication without getting laid upon in my nighttime tossing and turning.

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The pump should be placed on the same side as the sensor. That is one of the instructions given by Dexcom.

The pump, but the infusion set can be elsewhere.


Yes, the infusion set can be placed anywhere within reach of the tubing. That, however, is my only complaint about the new AutoSoft 90 infusion sets I have been sent. I have trouble detaching the tubing from the inset one handed. That has limited the locations I can use for the inset. Otherwise, the AutoSoft 90s are fine.


And I thought that was just me.

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Nope. Definitely not. The connection on Autosoft 90s is awful. There’s entire threads here singing the praises of Autosoft XC over the Autosoft 90s. They’re nearly identical in every way, except the connector is a little bit different and so much easier to use


My next sets coming are XCs. Lucky me

Did you have to order them special? The Autosoft 90s were sent to me unrequested. I thought the others were being discontinued.

I also find that the adhesive used is more difficult to remove. I find that it peels off some skin sometimes. That is not a good thing!

There was a shortage of XCs, and i was shipped autosoft 90s as replacement.

I had several unopened boxes of 90s when XCs became available again, and Tandem agreed to a trade of my 90s, and sent me XCs.

The supplier i got them from would not exchange.

I was so excited to find that Tandem would.

The XC has a larger bottom part, with rubber sides, compared to 90s. So it is easier to grasp, while other hand releases the part connected to tubing.

Ask Tandem for free sample XCs or possible exchange.


Robyn…Thanks SO MUCH!!

I had never even HEARD of Autosoft XC’s!!!

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Neither had I, until I read about them in a different group! The Autosoft 90s are the most popular set, so I think many suppliers just ship the Autosoft 90s to new patients without any discussion/information, and thus the Autosoft 90s remain the most popular set. At least that’s what happened to me. I was only asked how long I wanted my tubing.

I have yet to read of a single person who has tried both and actually prefers the 90s over the XCs, so keep spreading the word…

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Do you order from supplier or Tandem? Was your first order when they were having mfg issues from supplier? They had to substitute during that time.

When i first talked with Tandem rep, I had mentioned i didnt like the auto90s, since i had tried them with medtronic pump. I used Med quick sets, which i miss. Rep suggested and sent samples for me to try XCs before first order.

These were from a supplier. Not Tandem. Not a first order either. Have been using them through this supplier for the last 2-1/2 years. They sent the first ones when I suppose there was a scarcity. And they continued sending them. I will tell them of my displeasure and insist on getting the others unless, of course, they are not being produced anymore.