It looks like the cause might already be found, according to the posts by TylerV76, or at least a good suspicion. He writes: I’m currently speaking with Apple engineers and they are aware of the issue but its been so random they are not sure what the problem actually is. Seeing that it’s across multiple manufacturers, it’s almost impossible to pinpoint without a widespread issue. One thing to note though, our Ranger is not on their approved CarPlay list. Even though it is the exact same Sync system as other vehicles, one engineer believes that is the root of the issue but cannot explain why some phones work.
I’m not saying this is the issue, but it has been the issue in previous problems with CarPlay and AA. Not everyone implements design or development standards the same, as you know.
Another factor here is the newer Ranger, new Explorer, new Super Duty series (and Lincoln counterparts) have changed hardware for the BCM and some other components and software, including the APIM and screen. The old software settings do not work on some of the new models. I know that your F-250 is not that new, but maybe this is one of those design oversight issues that just appear because no one though it would matter. (Either on the Ford or Apple side.) It does not look like there is a solution on the horizon anytime soon, at least from information presently available.
Interesting, I will give that a look. I actually am pretty convinced this is way more widespread than Ford realizes (probably affecting most 2020 F-250 trucks), because the primary issue is that the microphone volume is too low, not that it does not work. You can certainly make calls with it, but the other person has to turn their phone all the way up to hear you. My wife says she cannot use her phone in hands free mode when I call on CarPlay, but if she uses it normally and cranks the volume she can hear me enough to get by.
Also with the lower microphone volume, Siri messes up what you say a whole lot more than it does when it’s working correctly (ie: in my old truck).
So I suspect most of Ford’s customers probably just suffer through the problem and do not realize that it’s actually something that can be fixed. Not sure I would have realize it was an issue if my phone hadn’t worked perfectly in my 2019 F-150 which I just sold. So I know how it should work, and I suspect most of your customers don’t and hence do not report this as an issue.
This will be easy for someone who has an F-250 2020 model to test and verify. Have someone with an iPhone connect to the 2020 F-250 unit in normal bluetooth mode so that works, then connect to CarPlay and make a call. While you are still on the call, unplug the CarPlay cord so it goes to normal bluetooth and if the problem is present, the other person on the other end will notice the phone call volume just went WAY up.