New to Dexcom...!

Hi folks,

just started using a Dexcom 7+ two weeks ago and got the error code "???" after inserting a new sensor. Spoke to our Hot-line in Germany but unfortunately they were not able to supply a satisfactory answer. We have very little experience here in Germany as the Dexcom became available around February this year so it is still pretty new this side.

I stopped the freshly inserted sensor and did a restart. After 2 hours I calibrated and since then it’s be up and running. The reason for inserting a new sensor after such a short period of usage (6 days for the first sensor) was the fact that the display froze on my receiver and I was not able to calibrate or see my values at all. The receiver however still gave all alarm signals but I could not cancel them or change them.

Is there someone out there that has experienced the same sort of hassles that I’ve had?

Due to the fact that I'm renting the Dexcom for a two month period to gain experience and have limited sensors (4 only) I I would appreciate any feedback what so ever.

Thanks Martin.

Hi Martin,

When you get a ???, it usually means that the Dex is confused with the info it’s receiving. Dexcom says to wait up to three hours for the ??? to be replaced with a bG value. Don’t attempt to restart it when you get ???, just be patient and rely on your fingersticks for the three hours. If it doesn’t snap out of it (or just dies, which can also happen) within three hours, and you’ve used that sensor for less than a week, Dexcom will send you a free replacement.

Hope this helps.


Hi etta,
Thanks for the Info. Forgot to mention, I waited over 10 hours, got pretty nervous so then I did a restart.
Spoke to the Dexcom Retailers here in Germany but they weren’t too keen on sending a replacement. When I contacted them later they were pretty relieved to hear that the sensor was up and running again. Hope this doesn’t happen too often in the future.
Thanks for the quick reply and Yes, I’m grateful for any tips and help I can get.

That stinks that they won’t replace one that dies short of a week. I thought that was standard practice for Dexcom.

I was always told they were guaranteed for 6 days. I’m in the US.