G5: replace transmitter w/out removing sensor?

So, I received a “replace transmitter soon” warning a few days ago, and didn’t freak because that always gives you some time to get it done. Plus I know it’s an artificial software limit, and if you have xDrip you can keep it going for weeks. Well… No. Woke up this a.m. to a “Your transmitter is dead” message, and when I switched over to xDrip it told me… “Your transmitter is dead.”

Fortunately I already received my next replacement, so I wasn’t, as they say, SOL. But dang it, I just started a sensor session like three days ago and really didn’t want to have to pull it out and use another. So I gave it a bit of a try, but my wife’s out of town, and despite various contortions in the bathroom mirror I couldn’t manage the feat of single-handed back-of-the-arm transmitter removal on my own, and I ended up yanking it all out and starting afresh anyway.

So this is all a little theoretical, but I thought I’d ask anyway: has one of you clever, experienced Dexcom mavens ever swapped in a new transmitter without pulling the current sensor? Is it even possible?

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Ancillary question: what’s up with the battery actually being dead? I’ve done the xDrip thing two or three times and there’s always been plenty of charge left after the official Time’s Up. Some people have kept 'em going for another couple of months.

Sure. From a system point of view, trivial. Same as restarting the sensor for another session. We did not do it that often but had to have been 2 or 3 times (on the G5) at least?

From a physical “reaching it” point of view? No. We have never done it solo. Always it was a two-person task.

It can be done using the plastic part (key) from inserter device.

This video shows it, although would be more challenging with sensor on arm.

Dexcom transmitter removal

(Starts around 1:50).


I’ve tried that plastic “key” thing several times and never got it to work. Maybe with a video I’ll finally be able to figure out what I’m doing wrong!

My other concern was about getting the new one to snap into place without that removable tab/lever thingy you get with a new sensor. Just shove on it until it clicks I guess?

When I do a new insertion, the lever thingy doesn’t always lock in both corners, so I manually lock them in, very easily. I just pry the corner thingy up (away from skin) and around the corner of the transmitter.

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I have done this a number of times. Especially when I was testing my G5 when I swapped the batteries in the transmitter out.
Getting both sides to release is kind of a pain. I usually just use the point of the plastic tool and do one side at a time. Seems to work a lot better and come out a lot easier.
As for clicking them back in. I just push them in by hand half the time anyways. No big deal. The little tab is nice and all, but definitely not needed.

Try practicing with a recently removed sensor with the transmitter still attached. Put it on a flat surface in front of you and practice using the removal key. You must insert this key at a very specific position. Take note of the tool’s position relative to the printed graphic on the back of the transmitter. Of course, having a flat table to push against (and using a second hand!) makes it easier but it is possible to do on the back of your arm with some practice.

I’ve only done this a few times and each time required some repeated efforts. If a personal assistant was available, I’d likely choose that route first.


T’other thing is that the new sensor is behaving absolutely bonkers, false-alarming me with lows dropping twenty points in a few minutes even after re-calibrating. I know the first 24 hrs can be a little erratic but nothing like this. Keeps insisting I’m dropping into the 60s when my finger-sticks are saying I’m cruising nicely at ~ 100. Doesn’t hurt like I hit a blood vessel or anything. The other sensor was nice ‘n’ stable and accurate. Really wish I’d been able to manage the transmitter swap instead!

I would give it 24 hrs (total - from time of insertion). Still bad data then call Dex Tech Support, have them send another sensor and swap it out.
I don’t think it will get better but my thinking of giving it 24 hrs is then you have no doubt it was just not going to work.

Bad sensor? Bad location? Bad weather? Full moon? Who knows. Bad data is bad data.

Once you have been on the Dexcom for some time, you know pretty fast if something is “not right”.

Is your question about physically taking out a transmitter and putting one back in, or about technically connecting the same sensor to two different transmitters? We easily take out and put back the same transmitter, but I don’t think we’ve ever crossed over a sensor from one transmitter to another. Hmm.

Five years in my case. Blood vessel weirdness does usually settle down after the first day, so I’m hoping it’s that. But this is being way crazier than I’ve ever seen. In the last hour I’ve gone from 67 to 84 to 67 to 83 to 64 to 96 to 68 to 114.

My transmitter failed after 6 weeks with a 2 day old sensor. Key for removing the transmitter was not to attempt to unlock both sides. I ended up unlocking one side only with my fingers and then pushing out the transmitter. Now I do it all the time so that my transmitter does not come in contact with UniSolve. No real reason for that. I just like it better. Putting the new transmitter in was much easier than removing it one-handed.

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Yes, getting the transmitter detached and swapping in a new one without removing the sensor.

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Closing the loop on this: the new sensor continued to swing wildly between high and low yesterday (I had a screeching urgent-low and a screeching urgent-high warning within half an hour of each other during a choral rehearsal last night, earning me many foul looks), to the extent that I had to turn off alerts. Decided to give it overnight to maybe settle down, but it was still whacky this a.m., so I pulled it. No blood, no swelling or pain at the site, just a schizoid sensor. This is actually a first for me–I’ve had bad insertions before but never a completely haywire unreliable sensor like this. Dexcom, as usual, was great about sending replacements, including one for the sensor I lost due to the transmitter change.


I inserted a new sensor two days ago and it has swung erratically high and low. Not as widely as yours did but certainly shades of that performance.

My calibration routine is to only calibrate with a fingerstick (FS) when CGM requests and if things are corresponding well, I even skip some calibrations. If CGM is greater than 20% off the FS, I’ll calibrate.

1:20 pm Inserted new sensor
3:23 pm Initial calibration FS 109, 113. CGM posts 109. - Looks good.
4:56 pm CGM 75, FS cal 107 - CGM > 20% off, so I cal to raise CGM.
6:50 pm CGM 46, FS cal 103 - CGM goes way too low. I cal to raise.
9:59 pm CGM 197, FS cal 120 - CGM goes way too high. I cal to lower.

5:43 am CGM 89, FS cal 61 - CGM goes too high. I cal to lower.
6:20 am CGM 50, FS cal 72 - CGM reading too low. I cal to raise.
11:50 am CGM 60, FS cal 76 - CGM reading too low. I cal to raise.
7:27 pm CGM 60, FS cal 77 - CGM reading too low. I cal to raise.

6:50 am CGM 101, FS cal 93 - CGM finally settles down @ 41 hours post-insertion.

From the initial double calibration start, I then calibrated twice to raise, then twice to lower, then three times to raise before it finally settled down at 41 hours after insertion. This is not typical for me but not rare, either.

I thought when I inserted at mid-day, it would settle down before bedtime. Unfortunately that didn’t work out.

It’s times like these that it feels like I’m fighting with the algorithm. But I think that the sensor just needed time to settle in. In the past I’ve sometimes inserted my sensor for 24 hours before starting the session. Some people call this a pre-soak. I think that practice would have helped in this instance. I think I’ll do that for the next few sensors to see if I have better luck. It’s hard to tell; many times starting without the pre-soak works just fine.

So, this comment is just a long-winded way to tell you that you’re not alone in this.

When I get a sequence like this with new sensor, I will do frequent calibrations (about 20 mins apart) until it gets more accurate. Best if during times where I don’t have food on board.

I am using G4.

Yeah, I’ve used this tactic, too. It usually works but I’ve also had readings that got worse, too, and forced me to give up and pull that sensor.

I’ve watched some sensors (when I can be patient) go down the wrong path and if I don’t calibrate, they swing back toward more reasonable numbers that then are more amenable to less drastic calibration techniques.

I also use the G4.

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Just my theory, but when starting a new sensor, I think the dexcom algorithm gives more weight to entered BGs. Once its been going for a while, gets more stubborn, and seems to rely more on its own history (since it has more), and responds less to input reading. So I may retest BG and determine if could be meter error.