iPhone is continually lowered when connect to GMC

TRyan8 · April 2, 2019

My iPhone has the volume turned down ever time I connect to my 2019 GMC AT4. I had the phone checked and all diagnostics came back fine. You have to manually adjust the volume on your phone when entering or leaving the truck. to avoid missing calls. Spent numerous hours trying to figure this out. It works fine in my wife's Ford Explorer. So, I took it back to the dealer to find it is a know problem and GMC has no updates to fix it. Has anyone experienced this and found a resolution, as I am confident after speaking to GMC that it a program coding issue for them.

O Town Denali · April 6, 2019

I started experiencing this same thing about 3 days ago. I have had my truck for about 4 months and it just started doing this.

I am on version V 509 and it has not updated since the end of Dec so I do not know what changed.

You can go to "sounds" and turn the "change with buttons" to off and you phone should still ring.

Edited April 6, 2019 by O Town Denali

Cmillerjr · April 8, 2019

The only time mine automatically lowers volume when connected is when it’s on silent.

MDSilveradoGuy · April 8, 2019

I am not sure it is necessarily an issue with the truck. What version of iOS are you running?

My 2015 Colorado with the IO4 stereo (4.2" display but BT/Streaming and everything else) started doing this with my iPhone Xs Max earlier this week - right after my last iOS update.

lebag335 · April 8, 2019

IOS 12.2 iPhone X in a Silverado Trail Boss LT. Lowers my volume on the phone to 2 bars every single time. Infotainment version is 509. I haven't yet received the update for 803.1.

O Town Denali · April 8, 2019

56 minutes ago, MDSilveradoGuy said:

I am not sure it is necessarily an issue with the truck. What version of iOS are you running?

My 2015 Colorado with the IO4 stereo (4.2" display but BT/Streaming and everything else) started doing this with my iPhone Xs Max earlier this week - right after my last iOS update.

I am thinking this is the issue to. I only started having this problem in the last 7-10 days and that is when I was upgraded to 12.2. Could be a coincidence though.

My truck updated to 803.01 yesterday and that did nothing for the issue.

Edited April 8, 2019 by O Town Denali

Z71RST · April 10, 2019

I'm having the same issue. I Just upgraded to IOS 12.2 Last night and this morning in my truck, it did the same thing again. So the last 2 versions of IOS has now dropped down to 2 bars on my volume. That leads me to believe it's the truck, not the phone or IOS. The only thing I've thought of doing is to turn off Bluetooth on my phone, and just plug it in and use the vehicles apple play. By far the most annoying thing that's happened since buying this vehicle. Side note, We bought a 2019 GMC terrain at the same time. It doesn't do this to my wife's phone or mine. Same 8" screen, hers however has navigation. My truck does not. Ready for them to fix this...

RSTPilot86 · April 10, 2019

Having the same issue as well, hopefully there's an update soon as it's rather annoying.

Loco-diablo · April 11, 2019

Is the issue your speaking of when connected via Bluetooth? Or CarPlay via a cable? Or both?

Sent from my iPhone using Tapatalk

BeardBros · April 13, 2019

I also have the same problem. iPhone XR with the latest IOS and 2019 HC with the latest update. As soon as I the phone links up to the truck Bluetooth it turns the phone volume all the way down. It pops up on the phone screen when it happens. I do not have this problem in my wifes 2015 Acadia Denali. I have played around with every setting and cannot come up with a solution besides turning my volume up after I leave the truck every time. Very annoying.

sicilit · April 17, 2019

i have this issue too. only on Bluetooth. If i have it plugged in it is super loud. My phone is normally on vibrate, so I will pay attention if it changes when I have the ringer on. I have iOS 12.1.2 and this has been this way since November when I first got the Truck. I have done 3 Infotainment Software updates so far.

2019silverado · April 23, 2019

I bought a 2019 High Country in November '18 and it's been lowering my iPhone 7 plus volume almost all the way down since day one. I've tried everything and have had 2 updates to the truck software since, and it still continues to lower the volume way way down. Very annoying.

econometrics · April 23, 2019

Are yall saying that the Infotainment system lowers the iPhone volume only when the phone RINGS? Or with music as well?

I have 803.1 and an iPhone XS 12.2 iOS, and this has never happened to me via Bluetooth connection.

sicilit · April 26, 2019

I had a 2019 LT Z71 as a loner with the smaller Infotainment screen than my truck and the phone volume was fine via Bluetooth. I had my phone on vibrate at the time as well.

6t4 · May 3, 2019

SO funny, I guess I am not the only one....OK GMC....read this board and update your software.......this is a major annoyance glitch! stop messing with the iphone volume control. let stand where it is set.....if it blows the speakers, right a software clipping signal software program for the amplifier circuit!