Multiple things can cause your GPS to malfunction completely or become inaccurate. Sometimes this can be caused by a software glitch. The simple solution to a software glitch is to reset your device by turning it off and then turn it back on again. If that does not correct the problem, try and get a clear, unobstructed view of the sky. If there are too many obstructions between you and the sky, it could cause the GPS to lose accurate signal. Obstructions would include; buildings, trees, mountains, caves, etc. If you have a clear line of sight to the sky and still have little or no GPS signal, your GPS unit within the device is most likely malfunctioning and needs replacing.