Unexpected Sensor Disconnections With 670G & Guardian 3


I am a user of the Medtronic 670G & Guardian 3, and they sometimes get unexpectedly disconnected for no obvious reason. Both have good battery charge, and the sensor is less than 7 days old (actually, only 3-4 days old). This happens at random times when I am just doing normal activities (just sitting around, they are not separated like when taking a shower). In most cases, they will reconnect automatically, but that sometimes takes up to around 10 to 15 minutes. Even though this does not cause it to exit Auto Mode (although it does switch to Safe Mode until they reconnect), it is obviously not a good thing to have happening. I will also mention that when starting a new sensor, it takes longer to find the sensor than I would expect it to. Has anybody else ever had unexpected disconnections with the 670G & Guardian 3? Thanks.


Call Medtronic and explain the situation, but I believe you will find it is a normal operation. I have seen mine disconnect for very brief periods, and maybe i am not understanding the issue. But I think it is normal and it should not require intervention.

I am a Medtronic ambassador. My opinions are my own. They did not pay me to say nice things. OK, they sent me a shirt and a cup but even I am more expensive than that.


Helpline people say that occurs when the sensor data is being processed. Usually the first and last days of the sensor. It’s scary to see no reading, no ISIG, but, hold tight, it will be fine. Hopefully.


I have heard if you keep your pump and your cell phone in the same pocket this can interfere with the signal, it happened to me once, but generally I have only seen this at the end of my sensor life. I had a pack of sensors in the garage for the summer and all of them did this after day 5-6. I think i fried some circuits with the 100* temps.

edit: just had my first one of these the other day it just lost connection for 15ish minutes then i bolused for dinner and by the time i was done it was back. i looked at the graph and it updated all the missing reading so it was still functioning just be normal operations or processing something.


I have also seen it happen and if I just ignored it then it would reconnect automatically, and if I had not been looking at my pump at the time it happened, I probably never would have known. The problem is in the cases where it does not reconnect fast enough, and then the pump gets angry (goes out of Auto Mode, asks for more Enter BGs, etc.)


Yes, the sensor does seem to disconnect when it’s processing. Shocking at first, but once you expect it, it’s OK. As for the pump picking up the sensor signal: When the sensor is warming up I turn it off and then make sure to turn it on again a few minutes before attaching. Usually works fine, but sometimes it does take 15 minutes or so. Alarming, but unless something is really wrong, it will pick up. If you’re not sure if the transmitter is attached well enough, be sure to recharge it before reattaching.


I just started my new 670g with the sensor about a month ago. What a pain! Just wondering if it gets any better. I tried the last version with the enlisted and was more than frustrated and angry with that darn system. Fast forward 3 years later and my Endo keeps telling me I need a CGM and the new guardian is a huge improvement. I find it just as frustrating. My sensor has not lasted more than 5 days. The latest was an alert at 4 am that my BS was 48 and to check it. I got up and checked and it was 168. Not even close. So then I got a message to change the sensor which I inserted less than 24 hours earlier. I can’t afford the time or money to change a sensor daily. Btw, the sensor was not in a location with movement or rubbing.