Adding minutes on Prepaid T-Mobile SIM card.
The most common reason a GPS tracker does not respond is that the Prepaid SIM card is out of time.

Step 1: Locate the trackers phone number that came on the credit card sized card included with the tracker.

Step 2: Visit https://tmobile.ecustomersupport.com/tMobile/gifting.aspx, refill the SIM with as little as $10 for 100 Pings or locates.

If you would like to check the balance of your SIM card you can call 1-877-778-2106 and follow the prompts.