The loss of GPS signal in a car navigation system may be caused by various reasons, including environmental factors, equipment malfunctions, or setup issues. Here are some common reasons and solutions:

Environmental factors: Vehicles may be driving in tunnels, under bridges, or in mountainous areas with weak signals, resulting in weak or lost GPS signals. The solution is to leave these areas or install GPS signal enhancers. ‌

Equipment issues: including improper or damaged installation of GPS antenna, equipment malfunction (such as incorrect software installation or loose hardware components), interruption of connection between equipment and network, etc. The solution is to check and adjust the antenna position, replace or repair the damaged antenna, contact the network service provider to solve the connection problem, or send the equipment to a professional repair point for maintenance. ‌12

Software and configuration issues: including incorrect or outdated map software settings. The solution is to update the map software or reset the GPS system. ‌

In short, solving the problem of GPS signal loss in car navigation systems requires investigation and handling from multiple perspectives, including improving the equipment's usage environment, inspecting and maintaining the equipment itself, and updating or adjusting relevant software settings.