What is the definitive root cause of USB CarPlay disconnects?

[robbidoo]

There are a bunch of threads on here with people reporting that USB CarPlay with their VW head units often disconnect. Some got around it by using a USB -> wireless adapter, others talk about replacing the USB port but that doesn't seem to always work.

Is there a definitive root cause to this issue?

Personally I have a Discover Media PQ running software 0361 (apparently 0369 is the lastest but I haven't been able to find an image to download) and it has always been flakey, but recently I can't get it to connect successfully at all. The HU sees the phone, starts to connect, then after a few seconds "iPhone disconnected". Tried many new cables etc.

Before I blow £500 on a Pioneer or similiar I would quite like to figure this out. I definitely have the "green" USB port in the comfort dash cubby, but I also know that it was retrofitted as the cable it's connecting to is pink. Still I don't believe this should be a problem in itself.

Would appreciate any pointers from anyone who has had this issue and resolved it!

 

[Lightrofit]

The most common cause is the USB cable. Only cables that are most likely to work are the ones that come with the phone or an authorised 3rd party cable like Belkin. Cheap Amazon/Ebay cables are usually junk.

Another less common issue is software but I always recommend sorting the USB cable first to ensure that you have a solid connection from phone to van.

 

[robbidoo]

Thanks. I was about to argue with this “never had a problem with cables elsewhere” then realised I probably haven’t used the data side of a cable for 5 years+

Will dig out a proper Apple cable and try, thanks.

 

[Lightrofit]

For Apple, an original apple USB-Lightning lead or Belkin are the only 2 I every recommend. Mainly because you can walk into an Apple store and buy Belkin of their shelf lol.

 

[Shaun Witts]

In my case I thought it was down to dirt in the Lightning port of my phone. After some initial problems when I first got the van (& had an earlier phone and maybe cheaper cables) it has been fine, but just recently has started exhibiting the same issue that @robbidoo explained. However, my wife’s iPhone worked OK using the same cable, and using headphones through the Lighting port was not affected. I cleaned the port with one of those brush-type toothpicks and that seems to have helped, as its working OK at the moment.
I wondered whether the OEM head units are more susceptible to signal variations that might be caused by dirt in the port connections?

 

[robbidoo]

Thanks @Lightrofit - I would never have believed it but a genuine Apple cable has sorted this. Thanks very much.

@Shaun Witts I think it's clear that they need a very clean signal perhaps due to compromises in the design of the USB splitter. Certainly no after market units I've used have the same issue. Either way very simple to fix luckily!

 

[Zave]

Assuming you are using a quality cable and still having issues... I've found blowing into all of the cable ends/ports helps blow out the dust and so far seems to do the trick.

 

[robbidoo]

Spoke too soon on this one - it's "better" in that it works maybe 80% of the time, but still getting disconnects. @Lightrofit you mentioned software as a possible remedy, is that something you offer personally?

 

[Lightrofit]

Spoke too soon on this one - it's "better" in that it works maybe 80% of the time, but still getting disconnects. @Lightrofit you mentioned software as a possible remedy, is that something you offer personally?

Hiya Robbidoo, I can and do offer SW updates on infotainment systems and control modules such as BCMs, ECUs etc. But, before that trigger is pulled, I'd check your iPhone for junk build-up in the lightning port. Where they sit in pockets they can get lint and dust in the port and this is then compacted by inserting the Lightning connector. Wrongly, I use a wooden toothpick to dig mine out infrequently but you can get cleaning kits or even get Apple themselves to give it a clean. Worth a go!

 

[robbidoo]

It’s not dirty and it’s a brand new phone