Problems with wired USB audio from iPhone

I own a 2018 Prius Prime Advanced Plug-in with all the "bells and whistles." For the past year or so ( I think -- may be longer ), I've been experiencing problems when connecting my iPhone to the car's USB port via a lightning-to-USB cable. Specifically, when the car first starts, usually the iPhone doesn't even show up in the available audio sources. When, after several seconds to several minutes ( it's highly variable ), my iPhone does show up, and after I select it, the car will repeatedly connect and disconnect from the phone and the iPhone audio source will appear and disappear. At first I thought it was the lightning-to-USB cable so I bought a brand new one but that didn't help. I get error messages such as "iPod error", "No music files found", "USB error" etc. Also, the head unit will sometimes reset itself. After about ten minutes of driving ( usually ), the iPhone will stay connected to the car and the music will play uninterrupted.

FYI, I have an iPhone 12 Pro Max. Also, I know that there is some type of maps and/or firmware update which I haven't installed because Toyota wants several hundred dollars for it and I didn't think it was worth the money, although, I may be forced to purchase it if it can solve my audio connection problems.

Lastly, I've tested my iPhone in other cars, such as a 2018 Dodge Journey which also has a USB port for audio and I don't have *any* problems.

If anyone else has experienced these issue or has a solution I'd greatly appreciate hearing about it.

Thanks,

jdb2

 

The reason I'm using a wired audio connection is that my Prius model does not support high resolution Bluetooth audio. Normal Bluetooth audio goes through a lossy compression phase before it's transmitted and the audio quality gets degraded -- not so with the cable. I have an iDSD Nano DAC. I guess I could use that and connect it to the AUX port but then I'd have to touch my phone every time I wanted to pause the audio or skip to another track.

jdb2

 

Well, my iPhone supports "high-definition" Bluetooth audio such as LDAC. The mandatory codec that is supported by most Bluetooth implementations is SBC and it's very low quality. Even though my phone is sending the audio data, when the phone is first connected to the car via Bluetooth A2DP, there is a bidirectional negotiation that falls back to SBC because the car doesn't support anything better -- both ends must support a specific codec before that codec can be used. Also, even with codecs such as AptX HD, the compression is still lossy, which is why I prefer the cable.

Thanks for the suggestion. Several other family members have iPhones and I could test them in my Prius.

Regards,

jdb2

 

Thanks for the suggestion AFAIK, nothing has been spilled on my iPhone. I also have a Lifeproof case which protects the Lightning port, but, I guess after a while there could be some dust build-up. I don't see anything in/on the port but I guess it wouldn't hurt to take an isopropyl alcohol lens cleaning wipe to it to remove any kind of residue.

jdb2

 

Well, I've tested the iPhone of a family member and the audio exhibits the same symptoms when my iPhone is connected. Specifically, the phone not showing up at all in the audio sources displayed on the head unit and constant disconnects until the car has "warmed up". I also get the same error messages such as "USB error", "iPod error", "Audio player not connected", "No music files found" etc. In addition, the head unit resets itself for no apparent reason. A new behavior that I noticed is that sometimes when I can get music to play, the audio player UI on the head unit is a black blank -- don't know what's causing this.

Here are the specs for the two iPhones :

( family member's )
iOS 16.3.1
iPhone SE
model no. : MHGJ3LL/A

( mine )
iOS 16.5
iPhone 12 Pro Max
model no. : MGCR3LL/A

The cable I'm using is new, but I guess I can try another one just to be thorough.

Do I have enough evidence for Toyota that something is wrong with the car's head unit and associated electronics? I'm not optimistic that the dealership will do anything as they'll probably get out of fixing the problem with the "couldn't duplicate the problem" excuse :|

jdb2

 

Again, thanks for the suggestion I have given it a cursory look and there was nothing obvious that stood out. I guess it couldn't hurt to use some canned air to blow out any dust and another isopropyl alcohol lens cleaning wipe to remove any sort of residue, as there *have* been spills in the car, but nothing that impacted the USB port AFAIK as the USB-to-lightning cable is usually always plugged in.

jdb2