Tandem Pump No Signal

I’ve had my Tandem Basal IQ pump about 8 months. Often my iPhone will alert me that my BG is falling. I check the pump and the insulin has not been suspended because of No Signal. I spoke to the Tandem local rep and she said that the phone Bluetooth would read the sensor signal first if it was close. About 30% of the time my pump does not suspend and I set a temporary basal of zero for a certain length of time. I am making efforts to put my pump and sensor on the same side of the body but I can’t say it is a lot better. If I did not have phone I do not think I would trust the pump alone to suspend when needed. Are any of you experiencing this issue.

Hi @synstokesyahoo-com Synthia, have you tried to work through the issue with why the pump is dropping the CGM signal? It could be the pump (Receiver) or it could be the dex transmitter. Given that your phone hangs on to the signal maybe the pump has a communication fault? I have heard that this is a tough one to troubleshoot so good luck!

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Sarah @synstokesyahoo-com, I personally have not had any problem with my pump suspending, both with Basal IQ and now with Control IQ.
The only time that I have “Lost Signal” is when sleeping and my arm is on top of my sensor. I change position, lay on my back for five minutes and the pump “reconnects” and fills-in the twenty minutes of missed readings. My t-Connect reports read that my usage percentage is at least 98% of the time - the m time, I presume, is the two-hour warm-up for new sensors.

I only have put my sensors on my abdomen, and I usually wear my pump when up-and-about clipped to my waistband, occasionally in a pocket, and when I sleem, my pump is clipped to the neck band of my t-shirt or in a shirt pocket when available.

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Hi @synstokesyahoo-com. I just started on BIQ just last week, using my pump as my receiver, and though it’s only been a few days I am loving it!
120 is - or was - my “tipping point.” Regardless of my basal rate, hitting that number was like flipping a switch that started me dropping (those blasted :arrow_down: arrows!!!), and I would sometimes find myself close to the 50s as I was desperately trying to bring them up. Usually with BIQ I find myself leveling off about 80, but on just a couple of occasions I’ve found myself at 70​:arrow_down::arrow_down:, which is disconcerting since even with the stopping of delivery at that point I’m still falling. It’s “only” happened a couple of times but still…
I am pretty sure they were the result of over-bolusing for a meal. I’m sure I counted right, and my pump did the calculation, so perhaps I need to tweak my carb ratio a bit to give me a little more of a cushion. My numbers have been in an excellent range overall aside from those low outliers so I don’t think it will hurt. Also, I’m not getting extreme highs from over-correcting the way I used to as I’ve general avoided lows otherwise.
All of which is to say, you might check your regimen to see if there are commonalities - it may or may not be your phone.
I’ll be on BIQ for a couple more weeks then strong up to Control - I’m hoping to avoid or lessen the post-meal spikes.

Make sure the pump is facing “out” and not with the screen against your body. Apparently the Bluetooth can’t receive the signal otherwise.

Learned that from tech support several years ago and it solved my problem.

Hope it helps you too.


I will try this. I always wear my screen in. I use a Lycra belt pouch and I do not like the clip facing inward. I wish there was someone way to remove the clip. I tried removing the pump holder all together but the writing on the underside of the pump flaked off. Thank you for the suggestion.

Wow Dorie. That is wonderful. I am ready for the control IQ also. Hard to get in to see endo right now. I have a low threshold of 100 before pump suspend. I find that the suspend will go off before my BG is back over 100. It sees the leveling off and shuts itself off. I am not comfortable with that and think I will set it to 120 also. When I start dropping it dropping it goes down fast. I usually take in carbs and not wait to see if the basal IQ takes care of the situation. I guess I have a trust issue. After managing it myself for 38+ years it hard to let go.

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I use the holder that came with my TSLIM pump and just tried removing my pump. It didn’t take much effort although I did have to push a little on the compartment under the charger door as I pried it off. Once it’s out you should be able to remove the clip.

Synthetic @synstokesyahoo-com, you can remove the clip. I took mine off to realign the pump orientation from horizontal to vertical
After removing the pump from the case, push down on the release and slide the clip out
Personally, I recommend CIQ without spending too long with BIQ. Just remember , at least the last that I looked, the update to CIQ can not be reversed.

My doctor had me set for CIQ and when I called the DNE with a question about training she said I should start with Basal and step up. I honestly wasn’tt sure why but it sounded like it wouldn’t hurt, and I could get comfortable with some new technology without making an irreversible commitment, if that makes any sense. Which it might not, but that’s my logic and I’m sticking with it :blush:. Anyway, I’m sending my doctor some records on Friday (1 week in) and next week and will ask about stepping up then. I’ve done the training and have my upgrade code, which is good for several more weeks.

I do have to get authorization from endo to update to CIQ, right?

This is exactly what Tandem says not to do. You can remove the metal clip from the case.

Yes. I found the process for BIQ and CIQ were the same - I pulled up Tandem’s website, clicked on a link and was taken to a form to complete with my info. Next step was for them to reach out to my doctor for a prescription, and when they received it I got a link to the online training.

Ah yes, the clip. For a company so astute with pump design, I’d expect them to partner with cleverer case companies. :wink:

I don’t use any holder normally - and aim for pockets or will tuck it into a SpiBelt or similar. Tandem pumps often fit into “non smart phone” cases and while u cant read the screen thru it, I have a few that are easy to wear and I just take the pump out to fiddle with it. Mostly though it just hangs out in a pocket.

Joe, you have run the same thing I was going to share. I have found my iPhone is a better receiver than my t:Slim pump. I am using Control-IQ and it works great. If my body were a clock face and my transmitter is in my left upper abdominal quadrant (11 o’clock with 12 being straight in front) my Tandem pump will drop signal if the pump is more than an hour or two out of alignment with the transmitter. My iPhone on the other hand can be on my right hip belt (about 4 o’clock). I have batted this around with Tandem and all they will say is the transmitter and pump need to be in the same quadrant of the body.

@synstokesyahoo-com, I use a cellphone case for my t:Slim. I have heard from Tandem to have the screen out. This does seem to improve Dexcom transmitter reception by the pump. The best way to get the case off of the pump is to press with your thumbs when the cartridge is out at the time of a cartridge change.

Hi @987jaj. I use my pump as receiver and the only communication issues I have found happen when I roll over on top of my pump or tuck it under my pillow in my sleep, or when I’m wearing denim and tuck the pump into the pocket on the opposite side from where the sensor is placed. Just denim and that particular placement - go figure. It sounds like you may have found a solution that will work for you - I certainly hope so.
You indicated the Bluetooth dropped after a couple of hours apart, which I was curious about because the pump or handheld receiver will drop readings after 20 minutes if they are separated from the sensor for more than 20 minutes or so (I guess even electronics get separation anxiety :flushed:!). Does bluetooth increase that allowed time apart? Not criticizing - just curious and trying to learn.

@wadawabbit, Wow, did I paint a poor picture. There is a term ‘watch your 6’ which means watch your back. It is used by military aviators. Let me paint the picture a little better. If the body is at the center of a clock face, your left is 9 o’clock, your right is 3 o’clock, your looking straight in front is 12 o’clock, and directly behind you is 6 o’clock.

Now, let me try again. If my transmitter is on my belly about 11 o’clock, Tandem has said the pump must be carried on my body somewhere between my left (9 o’clock) and no more to my right than just a little past my mid-line (1 o’clock). I hope this sketch of a body & clock face helps and makes sense. Hours are positions not time in this situation.

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Dorie, check for a new post with a drawing. 987jaj

I always wondered what “Watch your 6” meant - thank you for explaining, and for clarifying. I’m glad you found a method that works for you. Kind of a shame you have to keep things so relatively close but we do what we need to do to make things happen. Take care and stay well!