Tandem Diabetes Care has issued a voluntary correction for certain t:slim X2 insulin pumps due to a potential speaker malfunction that can cause the device to stop delivering insulin. The company reported that this issue, which triggers a "Malfunction 16" alarm, leads to the discontinuation of insulin delivery and ends communication between the pump and continuous glucose monitoring (CGM) devices.
If the error is not resolved, users may experience high blood sugar levels due to the halt in insulin delivery and loss of real-time CGM data. In severe cases, this could require medical intervention or hospitalization. Tandem Diabetes Care confirmed 700 adverse events, including cases of high blood sugar or situations needing medical attention, and 59 injuries related to this problem. There have been no reported deaths.
The company sent notifications with instructions to affected customers in the United States from July 22 to July 24, 2025. The notification is available online at https://www.tandemdiabetes.com/docs/default-source/legal/companyupdate/malfunction-16-speaker-issue-tslimx2-qsf0024231.pdf. Customers can also check if their pump is impacted by visiting tandemdiabetes.com/mal16-2025.
Tandem has informed the U.S. Food and Drug Administration as well as regulatory agencies outside the country about the corrective action. A software update aimed at improving early detection of speaker failure will be released soon. This update will also add persistent vibration alerts intended to reduce safety risks. Pump users will be notified when the update becomes available and are encouraged to complete it once released.
For questions about this recall, U.S.-based customers can contact Tandem Diabetes Care’s Technical Support Team at any time by email or phone. International customers are advised to reach out to their local distributor for further information.
The company noted that these forward-looking statements involve risks and uncertainties related to enhancing detection of speaker failure, timing of software updates, and ensuring all impacted customers receive and install the update.
The t:slim X2 pump with Control-IQ+ technology is intended for use in people aged two years or older who require insulin for diabetes management. It works with compatible continuous glucose monitors and automated dosing systems but should not be used in patients under two years old with Type 1 diabetes or under eighteen years old with Type 2 diabetes, nor those needing less than five units of insulin daily or weighing less than twenty pounds.
Users are instructed to follow all operating guidelines for system components to avoid incorrect dosing of insulin, which can result in either low or high blood sugar events.
More information on safety instructions can be found at tandemdiabetes.com/safetyinfo.
