Good evening…
I’ve got a 2015 Kia Picanto Chilli, and whenever I plug my phone in (tried both an iPhone 15 Pro and a Google Pixel 4 XL), it keeps connecting and disconnecting randomly. Super frustrating when I’m trying to charge or use CarPlay.
Is there any way to diagnose what’s going on or any fixes for this? Could it be a wiring issue, or should I just replace the USB port?
Any advise is welcome 
It’s possible that the port is broken. Updates or other problems with the program may cause USB ports to stop working.
To determine whether the problem is unique to your device 
, try connecting additional USB devices—such as flash drives or smartphones—to the port.If other devices function well, there may be an issue with the one you’re attempting to connect.
Make 
sure the infotainment system in your car has the most recent software updates. Sometimes, this fixes problems with connectivity
Examine the cabling that connects to the USB port carefully if you feel confident doing repairs yourself. Keep an eye out for any damage indicators, such fraying or loose connections. 
Should you discover any problems, you may need to get the wiring changed or seek advice from a qualified mechanic
It might be necessary to see a qualified mechanic if none of the aforementioned fixes resolve the issue. 
They are better able to identify the issue and offer an appropriate solution.