I did the following Modification to my USB that connects to CarPlay I actually had forgot about it because it’s been working good since. So my carplay2air dongle would also power on when the door was opened, locked the doors or put key in The ignition. This caused it not to boot up properly at times because the stereo needed to boot up first.
so what I did was buy this piece from amazon ANDUL USB Switch Extension Cable, Upgraded USB Extension Cord with On/Off Power Switch Cable For LED Strips, IOS System, etc
https://www.amazon.com/dp/B07T9BRNHW/ref=cm_sw_r_cp_api_i_XuhmEbBS7F1MA
It turns off the power to the usb when you flip the switch but data still passes through. I took this apart and connected a relay to the power wired from this switch. I then connected the power supply to the relay from the 12v power adapter in my center console. This 12v power only turns on when the ignition is turned on. Doing this lets the stereo boot up and power only turns on the dongle when I turn on the ignition. Works everytime now.
My only issue now is I get audio shattering about 5 minutes into using wireless CarPlay. I have to pause what I’m listening to for five seconds then unpause it and it works again.
My google map voice control started working all of a sudden. So that’s good now.
My vehicle is a 2015 GMC Sierra Denali w/ 2016 Carplay HMI upgrade. So, pretty much equivalent to jsm174. The 2016 Carplay upgrade for these vehicles requires swapping out the USB ports themselves and I only did that for the center console, so that's where my Carplay2air is located.
I ordered my Carplay2Air back in late December and just received it yesterday...blissfully unaware of all the issues. It actually worked out of the box, but I immediately upgraded it over the web (192.168.50.2) and it stopped working after that. (just a red light, no blue) This was quite frustrating considering I waited a month for it to arrive only to seemingly brick the thing within 5 minutes of opening the box. After reading through all 50+ pages of this thread last night, I was able to get it working again by doing the following:
1. Remove all the settings for it from my iPhone (Carplay & Bluetooth pairings)
2. Start my vehicle and let the radio start up.
3. Plug in my iPhone to the Carplay2air USB port and then plug the Carplay2air to my center console USB.
After the red light came on, I saw the blue light flash as well. Suddenly, it was offering a bluetooth connection to my phone (while plugged in to USB) under a new device name than before. After pairing it, it flipped over to wifi and has been working (with some bugs) ever since.
Here are the bugs and workarounds, which have already been described, but probably bear repeating for GM vehicles:
1. Don't plug the Carplay2air device in to the vehicle until the radio splash screen disappears. A more automatic method would be the relay setup that "2018 Denali" described. (Thanks for this, BTW! Great work!) Of course, having to plug something in defeats the whole purpose and I hope a forthcoming firmware update fixes the apparent startup timing problem.
2. Also as "2018 Denali" described, the audio glitches out after about 5 minutes of pretty flawless performance. Pausing the audio for about 5 seconds and resuming fixes it for another 5 minutes or so.
Bottom line: if you wanted a device that works as the Carplay2air website describes, this thing is just not it yet. But, I'm encouraged to keep it because it appears there are rapid updates being made and I think it's pretty much the only option anyway.
Thanks to everyone for posting their experiences which have helped me a lot. Fingers crossed a future update makes this thing worth the expense.
