Tandem Warns of Malfunction Risk in t:slim X2 Insulin Pumps

Tandem Diabetes Care has identified a wiring defect in certain t:slim X2 insulin pumps that can cause speaker failure, halting insulin delivery and disabling communication with continuous glucose monitors and the t:slim mobile app. The company has reported 700 adverse events and 59 injuries, though no deaths, and warned of hyperglycemia risk if the issue occurs.

Between July 22–24, Tandem notified higher-risk users, calling the defect “Malfunction 16,” and advised continued use with extra precautions. Affected users should switch to backup insulin delivery and request a replacement pump if a malfunction occurs.

Tandem plans a software update to improve early detection and add persistent vibration alerts. The FDA has not yet listed the correction in its recall database. This marks the device’s third significant safety alert in under two years, following recalls for a software flaw affecting insulin dosing and an app issue that drained pump batteries.

10-08-2025