CarPlay unresponsive after iOS 18 on GMC Terrain

Talked to apple engineer for over an hour of trouble shooting and problem solving, we got nowhere. However it is definitely a problem with CarPlay but one that GMC (or your car maker) needs to put an update out to fix.

It was suggested to me to reset my iPhone to a previous iCloud backup with iOS 17 until an update is available. I also found if I play my music and have my map running on my phone but disable CarPlay when I plug my phone into the car, my music will still play (CarPlay crashes without it being disabled and Bluetooth won’t stay connected) so that is something to try for now as well.

I contacted GMC online and was told to call the dealership I purchased the car through to ask about an update and report the problem. That’s on tomorrow’s list! Will report back if I think of it. But so far the best suggestion I have is to contact your dealership as well and hopefully many reports will get them moving on an update!

I found this thread while researching this issue for my mom. Her 2019 GMC Terrain was behaving the same way. After reading this I had her check what iOS she was on. She was on 18.1 but had 18.2 available. She updated to 18.2 and it appears to have fixed the issue for her.

Contact apple support (I did it through the app and was texting them so pretty easy) so it is a known issue- more people hopefully it’ll get fixed faster.

Things to do before contacting to make it faster:

• Force restart your iPhone: Press and quickly release the volume up button. 2 Press and quickly release the volume down button. 3 Press and hold the side button until you see the Apple logo (this takes around 10 seconds).
• Force reset CarPlay (I turned my car off for one minute then restarted)
• See if CarPlay in another car works (mine did)

I have a phone call with an engineer tomorrow and will report back if I think of it.

Talked to apple engineer for over an hour of trouble shooting and problem solving, we got nowhere. However it is definitely a problem with CarPlay but one that GMC (or your car maker) needs to put an update out to fix.

It was suggested to me to reset my iPhone to a previous iCloud backup with iOS 17 until an update is available. I also found if I play my music and have my map running on my phone but disable CarPlay when I plug my phone into the car, my music will still play (CarPlay crashes without it being disabled and Bluetooth won’t stay connected) so that is something to try for now as well.

I contacted GMC online and was told to call the dealership I purchased the car through to ask about an update and report the problem. That’s on tomorrow’s list! Will report back if I think of it. But so far the best suggestion I have is to contact your dealership as well and hopefully many reports will get them moving on an update!

Hey!! I also have a case open with Apple that has made it's way to engineering and I wanted to let you know that engineering has confirmed it is a compatibility issue with GMC and the iOS18. Keep the phone call and give them all the diagnostics they need, but they told me hopefully the issue will be resolved within the next iOS update!

I can confirm as well iOS 18.2 has fixed the issue in the gmc terrain.

[Edited by Moderator]

Check the GMC forums to see if it’s happening to a lot of people. There will definitely be threads about it if it is. No issues in my 2022 Buick Enclave or our 2024 GMC Arcadia so not sure if it’s necessarily a bug affecting all vehicles under GM or necessarily a full fledge iOS 18 bug affecting most users (GM has been so slow with proving head unit updates period from my experience so I always hold my breath if a new major iOS update will have trouble playing nice…especially if we need GM to push out an update because they will take their sweet time if they do it at all 😂). I also haven’t had any issues in a Toyota that’s in the household or 2 Nissans so far. I would wonder though based on your situation if it’s possibly an issue specifically with your car head unit or firmware even though it is currently up to date. Usually when it’s an issue from the iOS or Android OS it won’t work at all…that’s been my experience in the past at least. Is this happening with the iPhone 13 that shows under your post? Just curious because it may matter if only certain iPhone models with the iOS 18 update seem to be having issues versus the iPhone 16 models (my lack of issues has been with the iPhone 16 Pro Max and the 15 Pro Max on iOS 18…both using wired and wireless CarPlay but it seems like someone else posted they were having issues with CarPlay using one of the iPhone 16 models in maybe a VW recently). Not sure if doing a restore on your iPhone will help but I know if you contact Apple Support it will be one of the troubleshooting steps if they have determined that there is a bug that can’t be resolved until an iOS update is released.

I have the same issue with my Ford Explorer. The fix for me is to reset bluetooth on my iphone and hope carplay will reconnect without rebooting the phone. Odd thing now is my Airpods won't connect via bluetooth until I reset bluetooth on my phone. Common denominator is the iOS 18 upgrade.

Make sure you've installed the latest version of iOS, which has fixed issues for some:

Update your iPhone or iPad - Apple Support

Then if you are still having issues, you may contact Apple Support directly:

Contact - Official Apple Support

But it's likely GM will need to craft a fix.

I recently upgraded to iOS 18.2.1 -- this seems to have resolved the issue.

Yesterday, I drove over two hours in my 2019 GMC Terrain withoit CarPlay issue.

Good luck!

The issue is not specific to GM vehicles. The IOS 18 upgrade also prevents wireless car play connecting with Mazda vehicles. Fortunately, Car Play still works fine when connected by cable between my I-phone 14 and 2021 Mazda Miata. I do have the latest version of Mazda media firmware and the latest IOS 18.1.0. My Mazda dealer told me that Apple is aware of the problem and is working on it. And that many devices of many makes are affected by the problem. I too have an engineering case in progress. But I don't see this as being a vehicle manufacturer fix. There are too many vehicle makes affected.

I have the same problem with my Terrain and new iPhone 14 running on iOS 18. Changing cords, ports, resetting/factory restoring the car infotainment system, forgetting devices, restarting phone/car, making sure GMC updates up-to-date...nothing has worked! Music only seems to last the longest connected (7ish minutes), but maps or phone calls immediately reboots the whole system within 5-30 seconds. CarPlay worked perfectly fine with my iPhone 11 running on iOS 17.7. So it seems like from this thread it's an iOS 18 thing?

All to say, I have a call with Apple scheduled tomorrow and hopefully GMC after and hope to come back with updates...which unfortunately will probably be we have to wait for a new iOS update :(

I talked to Apple on Friday afternoon. They are well aware of the issue and have had many calls of this issue. He said they are working on this issue and hope to have a fix with the next update. His words were “in a week or so”. He seemed very sincere, so I am hopeful we will see a fix for this problem.

I’m seeing a number of complaints about this. Seems like some GM infotainment systems are having issues. You’ll probably need an update for the head unit.

Contact your dealer or GM headquarters.

If it works on any other manufacturer's head end, it's not Apple's issue.

Lots of auto manufacturers outsource their head ends to third parties; it's likely the same OEM provided the software for all the misbehaving vehicles' entertainment systems.

There should be nothing that any device can send a head end to cause it to reboot, as there is not a "reboot head end" command in Apple CarPlay.

Pure and simple, if the head end reboots for any reason, it's a bug in the head end.