this would seem to be the first step in solving this problem.
With the information you felt required to share, we not nothing about the GPS tracker, other than it does not function correctly for you
I recently bought a GPS vehicle tracker and I am having difficulty getting it to work. I have followed the instructions in the manual, but still not working. The instructions say that I am to send a text to the device "CENTER,000000,1876*******#. THE device replied, "CENTER OK". I should send another text to the device"123" or "POSITION#". The device should reply with the current location and a map link. The device did not reply. Can anyone assist me or tell me why the device did not reply. The SIM card has credit on it.