Medtronic cgm sensor problem

Ok, I’m curious. Can anyone tell me how to “fix” my Medtronic cgm “sensor alert”? Can’t find an answer in the manual or the website. I called 800 # twice. On hold both times for over 4 minutes…not a problem. Then got a busy signal. THAT’S a problem. I know how to turn off the alert, but would rather fix what’s causing it. Also, how long does one generally last? Mine “quit” after 3 days. Thanks.

Hi Miki,

Can you be more specific on the Alert you are experiencing? The Revel has quite a few and there are certain things you can do to manage the alerts. I have had mine for 3 months now.


The main one I kept getting was “sensor error”. Then it advised to look at the guide. Not any help at all other than to tell me how to turn it off. Also, how long does yours usually last? After 3 days mine said “sensor end”. CDE said it should last 7-10 days. This is my first sensor to use.

When you get the “sensor end” alert, just go into the sensor menu choose “sensor start” and then “new sensor” just like you do when you start a new one you just inserted. It will alert you to calibrate rather quickly and you won’t have to wait the whole 2 hours like you usually do. Also, once you hit 7 days, the transmitter will need to be recharged so you will have to charge it then put it back onto the sensor. I’ve only done this a few times. Usually by day 7 I’m ready to change the sensor!

Under what circumstances are you getting the “sensor error”? Occasionally I get them when I’m starting a new sensor. I think that it might have something to do with the sensor just not being totally “wet” yet but I could be wrong. Usually if I just ignore them it works itself out by the time I need to calibrate.

Thanks, Colleen! I’ve turned it back on. Might have to wait the full 2 hours though, since I’d turned it off.

“Sensor error” occurred off and on for the entire time I had it on. More so at the beginning. And I would get a wide range of ISIG numbers. I’m SURE it had nothing to do w/me!!! JK

I am determined to get this all going. Thanks for all you help. And if you think of anything else I need to know, send it on!

When I try to go over the 3 day mark, I usually end the sensor, re-charge the transmitter, then re-start the “New Sensor”. Don’t try to get more than 6 days. I was only successful once with this. I got to 9 days before it just didn’t track right.

Follow the guidelines concerning waiting:
After inserting the sensor, wait 10-15 minutes before attaching the transmitter.
After pulling the transmitter off the charger wait 30-60 seconds before attaching. I think it say 5-15 seconds, but I think I minute isn’t too much to ask.

Be also careful with insertion angle, there have been a few posts to group concerning how this negatively effects the readings.

Sensor error could also be due to placement on your body. I use my abdomen, and on occasion will use my upper thigh.
Be careful not to place the sensor too close to your navel or the infusion set. I once place the sensor and infusion set too close and wound up with numerous “LOW PREDICTED” alerts when in fact I wasn’t.

Lasting 7-10 days, not so much with the MiniMed. Others, such as the DexCom lasts 7 days. Hopefully your Endo is up to date with the technology. You can also look at the MiniMed group. You might fond some answers posted there.

We used to get sensor error when we tried to start the sensor too early. What has worked perfectly for us is we insert her sensor at night, attach the clam and then cover with tegaderm. We let it alone all night, and then in the morning before I take her BG, I start the sensor. By the time I get done taking her BG her sensor is ready to be calibrated.

This has pretty much eliminated sensor errors. If you get the alarm - Bad Sensor, it pretty much means that and you need to start over.

We also do what others stated below, which is when we get the sensor end message we just start a new sensor but never remove anything from under her tegaderm. So basically we are able to put it in and leave it there for 5-6 days without any problems even with daily baths, etc.

Thank you guys so much! It actually worked for a little bit.

I went swimming, so now I’m waiting for it to “warm up” after reattaching.

Just as an FYI - I get a lot (A LOT) of “sensor error” alerts. I find that ignoring them works quite well. No, I’m not being sardonic. I simply clear them out (esc, act) and then go to either sensor/sensor start/new sensor OR sensor/sensor start/find lost sensor. Either one resolves the issue.

miki -

you might try putting your sensor in a different location. i’ve had mine for about a month and the first week was awful with all of the sensor errors. when i started, i putting the sensor on my belly, but i’ve since moved to my side and lower back where i have way fewer problems. a medtronic rep also suggested inserting the sensor vertically rather than horizontally and that has been successful. just be sure to put it above your pants-line. while the medtronic people have to tell you that the sensor is only FDA-approved for the abs area, my trainers had all worn theirs on the backside…


OK! I finally talked to someone at MiniMed. After looking at my data, they determined that I had a faulty transmitter. I’ve since received a new transmitter and replacement sensors. So far, so good! Thanks everyone for all your hints. I’m using them!

My 13 year old got put on a CGM system and I want to know how it works and how well it reads.And if you know who can help me with censors.