Dexcom G6 Calibration Error Service Request

Please read carefully before proceeding to the form

Only use this form if you are using a t:slim X2™ insulin pump from Tandem Diabetes Care and have experienced a Calibration Error. If you have not already entered a calibration (fingerstick reading) between 20-600 mg/dL (1.1-33.3 mmol/L), please do so and wait 15 minutes. If you are still seeing the Calibration Error after 15 minutes, you may proceed with using this form. If your pump did not display the words “Calibration Error” please see below for help with other CGM issues or visit our Contact Us page.

For all other CGM issues


Who to Contact

CGM Applicator

Tandem For


Dexcom For

  • Physical Damage (e.g., Broken Needle, Cannula or Needle Retraction Issues, etc.)

  • Deployment Issue

  • Painful Insertion

CGM Transmitter

Tandem For

  • Pairing Failure (Alert 29)

  • Signal Loss (Between Transmitter and Pump)

Dexcom For

  • Physical Damage

  • Transmitter Latch Issues

  • Difficulty Inserting or Removing Transmitter

  • Low Transmitter Battery Alert

  • Transmitter Failed Error

  • Overheating or Shocking

CGM Sensor

Tandem For

  • Inaccurate CGM Values

  • Pump Will Not Accept Calibration Values or Other Calibration Errors

  • Early Sensor Expiration

  • Sensor Failure After Two-Hour Warmup

  • Pump Displays "---"

  • Pump Displays “No Readings”

  • Pump Displays “Sensor Error”

  • Pump Displays “Wait up to 3hrs”

  • Pump Displays Hourglass for More Than One Hour

Dexcom For

  • Physical Damage (e.g., Broken, Detached, Missing Sensor Wire, etc.)

  • Poor or missing adhesive

  • No Initial Calibration

  • Sensor Failure During Two-Hour Warmup

  • New Sensor Inserted, but Displays “No Restarts” (Alert 25)

  • Bruising, Bleeding, Skin Reactions or other Discomfort

Did you know that Dexcom offers free overpatches to provide extra protection and durability for their CGM sensors? You can order these overpatches here: Overlay Patch Form.