How to fix garbled Bluetooth connection with carphone after iOS 15.4.1 update on iPhone 12 Pro Max?

If CarPlay doesn't detect your iPhone, make sure CarPlay isn't restricted. Go to Settings > Screen Time > Content & Privacy Restrictions. If Content & Privacy Restrictions are turned on, tap Allowed Apps and make sure CarPlay is enabled. Go to Settings > General > CarPlay, tap your car, and then tap Forget This Car.

If you need help with CarPlay - Apple Support (IN)

Search for accessories that have completed MFi certification. Once an accessory has completed MFi certification requirements and is reported to Apple as sold/distributed, it will be searchable in our public database of authorized Lightning, headset, charging, iAP-enabled, and Find My network-enabled accessories.

Learn how to identify counterfeit or uncertified Lightning-based accessories.

On your device, go to Settings > Bluetooth and turn on Bluetooth. Stay on this screen until you've completed the steps to pair your accessory.

Pair a third-party Bluetooth accessory with your iPhone or ...

If you're still having trouble with your car's audio system using CarPlay or Bluetooth, try the Aux cable. To get it fixed, there are two options:

1. Take your car to a reputable car dealer or car audio specialist. They have experienced technicians who can diagnose the problem with the Aux cable. This could be a loose connection, a faulty cable itself, or an issue with the system's Aux port. They'll be able to repair the issue or recommend a replacement cable if needed.
2. Consult your car's infotainment system manuals. These manuals often include troubleshooting sections that might address common Aux cable problems. You might find instructions for resetting the system, cleaning the Aux port, or confirming the cable's compatibility.

Before taking your car to a dealer, it's always a good idea to check the manuals first. This can sometimes save you time and money if it's a simple fix you can handle yourself. However, if the manuals don't offer a solution, or you're uncomfortable tinkering with the system, then a car audio specialist is the way to go.

Refer to the list of cars that are compatible with CarPlay --> iOS - CarPlay - Available Models

Same - I can hear them fine, and connect fine to the car Bluetooth, but no one can hear me clearly. All different phones on their end and they hear me "muffled" and "garbled" they're telling me. Dealership had us troubleshoot a bunch of steps, nothing worked. This wasn't an issue prior to the last update. Andriod phones are clear when connected to my car, both directions. Just my iPhone 12 is having the issue (with the last update). I've deleted the connection and repaired, no difference. I'm at a loss as to what to do next.

It's not always the iOS update's fault!  Many things can cause phone problems.  If you tell people you think it's an iOS update, it might make it harder to fix or find a solution for the real issue.

Remember, the right question often leads to the solution!

Was/Is your device Jailbroken? If that's the situation, please be informed that attributing the issues to iOS updates may not be accurate.

iOS updates aim to enhance user experience, boost security, and fix bugs rather than disrupt core features. The majority of the issues after updates might stem from underlying, unmentioned factors. Updates won't typically alter personal data but may refine settings or features. Backup before major updates for safety. Review Apple's update details and backup advice for a smooth process.

Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update affected the iPhone functions.

Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.

See what each update does: About iOS 18 Updates, About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...

My iPhone is garbled to people I call from my auto bluetooth. My husband's android has no issue.