Sensor and transmitter frequently asked questions

Request a sensor replacement on Diabetes.shop.

Tip: Get your sensor lot number ready before you begin the process. You can find this number on the sensor packaging. Watch the video below for more information.

If you are still experiencing issues, you can request a replacement.

See how longtime Medtronic customer, Rob, inserts the Guardian™ Sensor 3 on the back of his arm.

Watch this video for tips on inserting your sensor on your arm with the help of a partner.

If you do not see a green light, follow these steps:

1. Try to disconnect the transmitter, wait for several seconds and then reconnect. If the green light still does not flash, charge your transmitter.
2. If that doesn’t work, double check to make sure the sensor is fully inserted into your body, and review the technique on how to insert correctly. Check out the Changing Your Sensor video for steps on how to insert correctly.

Each sensor requires 2 pieces of tape.

Yes, it’s recommended that you use the 2 pieces of tape included with your sensor. There should be a piece of tape covering the sensor and a piece of tape covering the borders of the transmitter. This ensures that the transmitter doesn’t pull away from the body if it gets caught on something, for example, clothing.

Different tapes and adhesives are available to hold the transmitter in place and you may need to try different products to find the right one for you. You can review the list of additional tapes in Tape tips and site management or check out tapes available on Diabetes.shop.

You can purchase adhesives and tapes at Diabetes.shop or through the product manufacturer’s website. Here is a full list of product recommendations.

Contact 24-Hour Technical Support at 1-800-646-4633 option 1 for technical assistance or to report product issues. They can also provide a sample kit with various tapes and adhesives.

• Change the sensor and insert it into a different location.
• Avoid sites where clothes may rub, where your body bends a great deal and your beltline if possible. These areas present a higher risk of the sensor and transmitter being accidentally pulled out.
• Do not insert the sensor into an area that is lean, scarred, or hardened. If inserted in these areas, it may decrease the flow of interstitial fluid, or the sensor may kink.
• Try different orientation for the sensor and transmitter. For example, insert so the sensor is on the bottom and the transmitter sits on top. This orientation may help prevent a teeter-totter action at the sensor and transmitter connection which could lead to a lost signal.

Allergies and skin reactions such as itching, rashes or bumps may occur. When you notice them, determine the cause and use a different product. If the site becomes irritated or inflamed, the set or sensor should be removed and inserted in a new location.

Check out our helpful Tape Tips and Site Management.

Before applying tape, apply pressure to the sensor insertion site until the bleeding has stopped. Once stopped, wipe away the excess blood gently, dry the area, then apply the tape. If there is too much blood, change out your sensor. If bleeding persists, please contact your healthcare provider.

• MiniMed™ 780G system
• MiniMed™ 770G system
• MiniMed™ 670G system
• MiniMed™ 630G system

• A Calibrate now alert occurs when a calibration is needed for your sensor to continue reading. To clear this alert and to continue receiving Sensor Glucose (SG) values, simply enter your current BG and calibrate.
• A BG required alert occurs when a BG is needed for the SmartGuard™ Auto Mode feature in the MiniMed™ 670G or 770G system to continue running safely. As soon as you enter a new BG, SmartGuard™ Auto Mode will resume (indicated by the blue shield on your home screen).

Select your sensor to get information about the Sensor Updating alert:

• Guardian™ 4 sensor
• Guardian™ Sensor 3

CGM alerts at night may be caused by a few different reasons ranging from sensor insertion to site placement. Here are a few tips to help prevent getting CGM alerts in the middle of the night.

• Sensor insertion, site placement, and taping make a difference. For your sensor to work its best, avoid sites where clothing may rub or constrict, where your body naturally bends which may cause the sensor to pull out and where there is a lot of pressure. See how to insert and tape the sensor properly.
• If you use the Guardian™ Sensor 3, know your calibration status. The calibration icon shows how much time is left until your next scheduled calibration is due and calibrating before bed helps reduce the chance of needing a calibration overnight while sleeping.
  • Plan ahead. Sleeping in on the weekend? Summer schedule different from the rest of the year? If your schedule changes, think about how your calibration schedule may need to be adjusted to help avoid any unwanted alerts and alarms.
• Customize nighttime alert settings. Talk to your healthcare team about high and low glucose limits overnight to make sure alerts are personalized to meet your needs. You may consider setting both high and low limits differently for the overnight period.
• Consider the Alert Silence or Mute All Alerts feature.
  • Your pump has a feature called Alert Silence, where you can temporarily silence alerts. Don’t worry, you will still get important low alerts if Alert Silence is ON. For your safety, Low SG (50 mg/dL or below on the MiniMed™ 670G/770G systems, 54 mg/dL or below on the MiniMed™ 780G with Guardian™ Sensor 3 and 64 mg/dL or below on the MiniMed™ 780G with Guardian™ 4 sensor) as well as High SG (250 mg/dL or higher for more than 3 hours) will always sound, and Alert on Low will sound if it’s turned on. Learn how to set Alert Silence for the MiniMed™ 670G system, the MiniMed™ 770G system, and the MiniMed™ 780G system.
  • Your Guardian™ Connect system has a Mute All Alerts feature where you can temporarily mute all alerts. You can prevent alerts from making any sound by going to Menu > Mute All Alerts to silence all your alerts for up to 4 hours. None of your alerts will make a sound for the entire time that you choose, except for the Urgent Low Sensor Glucose which will vibrate for your safety.

When an alarm occurs, something has been detected that is preventing insulin from being delivered. This must be addressed right away. Alarms cannot be silenced.

Your pump has a feature called Alert Silence, that allows you to temporarily silence glucose alerts. Select your system below to find instructions for how to silence glucose alerts:

MiniMed™ 780G system
MiniMed™ 770G system
MiniMed™ 670G system
MiniMed™ 630G system

Your Guardian™ Connect system has a Mute All Alerts feature where you can temporarily mute all alerts. You can prevent alerts from making any sound by going to Menu > Mute All Alerts to silence all your alerts for up to 4 hours. None of your alerts will make a sound for the entire time that you choose, except for the Urgent Low Sensor Glucose which will vibrate for your safety.

If you receive a “Calibration not accepted” alert, it means that the pump couldn’t update your sensor using the blood glucose (BG) value you entered. This could be because:

• The BG entered was not within a range the system was anticipating.
• Your blood glucose levels were rapidly changing.
• You may have used delayed or incorrect BG entries.
• It may be an indication the sensor is not working properly.

If you receive a “Calibration not accepted” alert, wait approximately one hour (or until your glucose is stable) to recalibrate. If you receive “Calibration not accepted” a second time, a new sensor will likely be required. If you have recently eaten, exercised, or taken insulin, you might need to wait a little longer than an hour.