Tslim x2: "Invalid Transmitter ID"

Hello everyone! I currently have the Tslim x 2 pump along with the Tandem CGM. Today when I started a new sensor I received the “Invalid Transmitted ID” I’ve been on this system for 6 months and this is the first time this has happened. I popped out the transmitter and stopped the sensor for 3o min, then restarted. I’m still getting this message. Any ideas? Thank you for your help!

Is it a new transmitter, or the same one you used for your last session? Double check that it actually matches what’s programmed under “my CGM”. If you wait until you see a new data point show, you can remove the transmitter quickly and look without stopping the sensor or interfering with anything.

Did you actually stop the sensor session before you removed the transmitter? Sorry if that’s a stupid question, but you didn’t actually say it and I’m covering bases.

I’ve seen this pop up a few times on the Facebook groups, and tandem tech support usually has then do a reboot and sends them a new transmitter (ask for a sensor, too, since r rest of your current one is useless) if it doesn’t resolve itself. If you don’t want to wait on hold with them, just plug in the usb charger and hold the silver button until it turns off, wait a few minutes to clear short term memory, then power it back on with the silver button.

Warning, you’ll have to reload and fill your cartridge/tubing again, though, so it’ll cost you some insulin. Tech support probably won’t make you do it a second time though, if you already tried it. At least they never made me do it again.


Hi Robyn,

It’s the existing transmitter. Yes I stopped the sensor session. Thank you for your help! I will call Tandem in the morning.

Technical support is 24x7 if you want to call tonight.

I suggest you stop sensor, clear trans id, clear BT connection (unpair). Then try again to get paired.

Do you have phone dexcom app linked to transmitter that is working?

Yes I have the app. When I restarted the sensor the app kept spinning saying “connecting to transmitter” but never did.

Also should I pop the transmitter out for 20 min before I clear everything and restart sensor?