how to fix maps using GPS in my care inconsistently stops working; says no internet

It sounds like you're experiencing an issue where the GPS navigation through Apple CarPlay on your car's system intermittently stops working and displays a "no internet" message. This can be quite frustrating, but there are a few things you can try before going for the software upgrade or service dealer check.

Here are some troubleshooting steps you might consider:

1. Ensure that your iPhone has a stable internet connection. Sometimes, connectivity issues on the phone can affect CarPlay's performance. Try restarting your phone or toggling airplane mode on and off to reset the network connections.
2. Disconnect and reconnect your iPhone to CarPlay. Sometimes, resetting the connection can resolve temporary glitches. Also, check if there's any debris or dust in the USB port of your car or on the charging cable that might hinder a proper connection.
3. Ensure that both your iPhone's iOS and your car's software are up to date. Software updates often include bug fixes that could resolve issues with CarPlay.
4. Sometimes, signal interference or obstructions can affect GPS signals. Try using CarPlay in different locations to see if the issue persists.
5. Sometimes, network settings on the phone can cause issues. You can reset them by going to Settings > General > Transfer & Reset > Reset > Reset Network Settings. Keep in mind this will reset Wi-Fi networks and passwords, so make sure you have them handy.
6. If none of these steps resolve the issue, visiting your service dealer might be necessary. They can perform diagnostics and check if there's a need for a software upgrade or if there's a hardware-related issue causing the problem.

Before opting for the dealer's service that incurs a cost, you might want to exhaust these troubleshooting steps or even consult with another dealer or specialist to get a second opinion on the matter. It's also beneficial to keep track of when and where this issue occurs as that information can be helpful during diagnostics.

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you and re-post.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

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