[GUIDE] [NO ROOT REQUIRED] [EPIC UPDATE] How to add VoLTE support for other carriers to the G8 (and other Qualcomm powered LG devices too!)

Search This thread

wheelzinmotion

New member
Apr 4, 2022
1
0
I own an AT&T "network locked" LG G8 and was able to use it with H2O Wireless (AT&T reseller) since I purchased it brand new in the sealed box back in late November 2021. Everything was absolutely fine until 3G was turned off back in March, where I couldn't place nor receive calls. I called H2O support and after explaining instruct me to recreate the APN, and after I did so I could place and receive calls for just a few minutes. So I called H2O again and decided to send me a new SIM card. A few days later I received it, activate it and still the same thing, so I put my G8 to the side. Fast forward to this past weekend, I called H2O again and this time they told me I had to create the following two APNs:

Name: H2O Internet
APN: prodata
MMSC: http://mmsc.mobile.att.net
MMS proxy: proxy.mobile.att.net
MMS port: 80
APN type: default,mms,supl,hipri
APN protocol: IPv4

Name: H2O Call
APN: nxtgenphone
MMSC: http://mmsc.mobile.att.net
MMS proxy: proxy.mobile.att.net
MMS port: 80
APN type: default,mms,supl,hipri
APN protocol: IPv4

The thing is that the only way I could place and receive calls is by selecting H2O Call APN, but don't have any data, and if I choose H2O Internet I get data but no calls.

Yesterday a friend let me borrow his AT&T SIM for a couple of minutes to do some testing and for the first time ever I could see a new icon on my screen that showed VoLTE. I was able to place, receive calls and have all LTE data that I want using AT&T's default APN. Right now I'm out of ammo wondering if there's a workaround to fix this VoLTE issue...

Any idea will be more than welcomed ! ! !
 

surgemanx

Senior Member
Jan 29, 2022
172
31
I own an AT&T "network locked" LG G8 and was able to use it with H2O Wireless (AT&T reseller) since I purchased it brand new in the sealed box back in late November 2021. Everything was absolutely fine until 3G was turned off back in March, where I couldn't place nor receive calls. I called H2O support and after explaining instruct me to recreate the APN, and after I did so I could place and receive calls for just a few minutes. So I called H2O again and decided to send me a new SIM card. A few days later I received it, activate it and still the same thing, so I put my G8 to the side. Fast forward to this past weekend, I called H2O again and this time they told me I had to create the following two APNs:

Name: H2O Internet
APN: prodata
MMSC: http://mmsc.mobile.att.net
MMS proxy: proxy.mobile.att.net
MMS port: 80
APN type: default,mms,supl,hipri
APN protocol: IPv4

Name: H2O Call
APN: nxtgenphone
MMSC: http://mmsc.mobile.att.net
MMS proxy: proxy.mobile.att.net
MMS port: 80
APN type: default,mms,supl,hipri
APN protocol: IPv4

The thing is that the only way I could place and receive calls is by selecting H2O Call APN, but don't have any data, and if I choose H2O Internet I get data but no calls.

Yesterday a friend let me borrow his AT&T SIM for a couple of minutes to do some testing and for the first time ever I could see a new icon on my screen that showed VoLTE. I was able to place, receive calls and have all LTE data that I want using AT&T's default APN. Right now I'm out of ammo wondering if there's a workaround to fix this VoLTE issue...

Any idea will be more than welcomed ! ! !
One user was having the same similar issue,and he crossflashed his G8 to the factory unlocked firmware.He said it worked without doing any modifications.This is the firmware he used below.That is odd being that H2O is an AT&T MVNO and calls not working.I used to use them myself back around 2015 if I remember correctly.

 

Zoki88

Senior Member
Feb 26, 2017
105
11
When i activate mbn file through PDC, should i see VoLTE sign immediately on phone, or need to restart phone every time? Also, should i testing mbn files that are already in my phone till i get VoLTE sign, or delete them all and adding ones from other(op5, pixel 2)mbn files? Also how can i know/find mbn file that i added from other mbn, as i don't see anything new i added from op5 mbn for vodafone india, but this one still here which was from my phone anyway?
 

Attachments

  • Capture.JPG
    Capture.JPG
    111.3 KB · Views: 31

and_rew

Member
Feb 18, 2018
5
1
Eugene
LG Velvet
Hello,

I think I need some help. I'm trying to create the folder from the kdz file in the fifth step, but I'm only getting a .dz file instead. I'm trying to get the MBN files from the LMG900TM version on to my LMG900UW (LG Velvet 5g). Is this even possible? My carrier is telling me that I have to "upgrade" to a new phone in order to use VOLTE. I just bought this phone November 2021. Please help?
 

surgemanx

Senior Member
Jan 29, 2022
172
31
Hello,

I think I need some help. I'm trying to create the folder from the kdz file in the fifth step, but I'm only getting a .dz file instead. I'm trying to get the MBN files from the LMG900TM version on to my LMG900UW (LG Velvet 5g). Is this even possible? My carrier is telling me that I have to "upgrade" to a new phone in order to use VOLTE. I just bought this phone November 2021. Please help?
Once you extract the .kdz you'll get the .dz file.Then that has to be extracted then unzip modem_a or modem_b.Either will work.I'm downloading the T-Mobile 20e file for the Velvet.I'll post back with the modem files you need.Oh,just thought of this.I highly doubt it will make it work being a Verizon variant.I have the same one,and I use it as a backup device with a Tracfone sim...lol...
 
Last edited:

and_rew

Member
Feb 18, 2018
5
1
Eugene
LG Velvet
Once you extract the .kdz you'll get the .dz file.Then that has to be extracted then unzip modem_a or modem_b.Either will work.I'm downloading the T-Mobile 20e file for the Velvet.I'll post back with the modem files you need.Oh,just thought of this.I highly doubt it will make it work being a Verizon variant.I have the same one,and I use it as a backup device with a Tracfone sim...lol...
Mine is a Canadian variant. I made a typo because I'm so flustered! I have a LGM900UM not UW. UM has the same bands that t-mo has. I'm actually on Simple Mobile, but they currently use the same network as t-mobile. At any rate, thank you for helping out!
 

surgemanx

Senior Member
Jan 29, 2022
172
31
Mine is a Canadian variant. I made a typo because I'm so flustered! I have a LGM900UM not UW. UM has the same bands that t-mo has. I'm actually on Simple Mobile, but they currently use the same network as t-mobile. At any rate, thank you for helping out!
Okay now we're talking with the UM model.I have the UW and it worked fine on T-Mobile's 3g,but after July I knew it was done for so I swapped it to a pre-paid Verizon sim.But,try these and let me know how it works out!
 

Attachments

  • Velvet MBN Modem Files.zip
    162.3 MB · Views: 9

and_rew

Member
Feb 18, 2018
5
1
Eugene
LG Velvet
Okay now we're talking with the UM model.I have the UW and it worked fine on T-Mobile's 3g,but after July I knew it was done for so I swapped it to a pre-paid Verizon sim.But,try these and let me know how it works out!
alright, everything installed smoothly! i rebooted the phone and the hidden menu does in fact state that MCFG is enabled and the carrier is TMO. i am also picking up 5G for the first time!! this technique worked for my Canadian LGM900UM!
 
Last edited:
  • Like
Reactions: surgemanx

and_rew

Member
Feb 18, 2018
5
1
Eugene
LG Velvet
alright, everything installed smoothly! i rebooted the phone and the hidden menu does in fact state that MCFG is enabled and the carrier is TMO. i am also picking up 5G for the first time!! this technique worked for my Canadian LGM900UM!
update: i still cannot tell if i have volte enabled or not. there is no toggle in any of my call settings, even after i enable them to display in Field Test>GPRI VoLTE/VoWIFI>UX
 

Zoki88

Senior Member
Feb 26, 2017
105
11
When i activate mbn file through PDC, should i see VoLTE sign immediately on phone, or need to restart phone every time? Also, should i testing mbn files that are already in my phone till i get VoLTE sign, or delete them all and adding ones from other(op5, pixel 2)mbn files? Also how can i know/find mbn file that i added from other mbn, as i don't see anything new i added from op5 mbn for vodafone india, but this one still here which was from my phone anyway?
I made mistake here as you were right earlier when you said that for lg can't put any other device's mbn files, but how does it work when i try using efstool when i put those others mbn in that folder, does efstool method works on lg at all?
 

Zoki88

Senior Member
Feb 26, 2017
105
11
Hello,

Does anyone know what the following message means:

QueryListConfigs failed with Gobi error code: 16 (Malformed QMI response recieved)

This occurs after activating a profile, which ends up being activated after I click on.

Thanks
I was googleing for this same error, and found out that only here is mentioned, but that error was appearing to me from time to time, not every time i connect my device. Btw i tried to put mbn file from LG Velvet in PDC for my V30 as that device support VoLTE in my carrier, neither that worked, so for LG devices is required to mbn files be from same device as @Wish39 told, not even devices from same brand. When it comes to efstool, that doesn't do anything, guess LG is locked when it comes to using those ways of enabling VoLTE(registering IMS, maybe/probably because of their own LG IMS app), not alike OnePlus, Pixel, or ROG Phones, where you can actually put mbn from other devices and testing through PDC and efstool. So if anyone reading this, it's not worth trying to enable VoLTE on LG using mbn from any other device(including other LG devices) no matter if through PDC or efstool, while efstool doesn't do anything no matter what. Only chance to enable VoLTE is to add mbn from your same device from other OS through PDC like this tutorial is for that if you don't have those mbn files in device already. I'll now go back to Asian OS as i don't see point of having Europe OS, battery is draining faster, and on original OS my phone gave best performance in terms of wifi.

Btw if anyone's interested and know something about making VoIP recording module which would works in any app, can you take a look on this thread? https://forum.xda-developers.com/t/...ule-to-bypass-audio-recording-limits.4416297/
Only Boldbeast's VoIP recorder (for now) can record in any app (for example only app that can record discord vc, skype, zoom etc), but his app is outdated, and he's inactive, not replying on mail or dm or anything, so we trying to get/make some alternative, any help much appreciated!
 

surgemanx

Senior Member
Jan 29, 2022
172
31
I was googleing for this same error, and found out that only here is mentioned, but that error was appearing to me from time to time, not every time i connect my device. Btw i tried to put mbn file from LG Velvet in PDC for my V30 as that device support VoLTE in my carrier, neither that worked, so for LG devices is required to mbn files be from same device as @Wish39 told, not even devices from same brand. When it comes to efstool, that doesn't do anything, guess LG is locked when it comes to using those ways of enabling VoLTE(registering IMS, maybe/probably because of their own LG IMS app), not alike OnePlus, Pixel, or ROG Phones, where you can actually put mbn from other devices and testing through PDC and efstool. So if anyone reading this, it's not worth trying to enable VoLTE on LG using mbn from any other device(including other LG devices) no matter if through PDC or efstool, while efstool doesn't do anything no matter what. Only chance to enable VoLTE is to add mbn from your same device from other OS through PDC like this tutorial is for that if you don't have those mbn files in device already. I'll now go back to Asian OS as i don't see point of having Europe OS, battery is draining faster, and on original OS my phone gave best performance in terms of wifi.

Btw if anyone's interested and know something about making VoIP recording module which would works in any app, can you take a look on this thread? https://forum.xda-developers.com/t/...ule-to-bypass-audio-recording-limits.4416297/
Only Boldbeast's VoIP recorder (for now) can record in any app (for example only app that can record discord vc, skype, zoom etc), but his app is outdated, and he's inactive, not replying on mail or dm or anything, so we trying to get/make some alternative, any help much appreciated!
Zoki88 if you need the MBN files for the V30 I'll post them here.I have a full LUNS backup of the last firmware released for the AT&T V30 variant as well if you need it?I was true to my V30 when AT&T pulled their b.s. and wouldn't let the VoLTE work unless it had "their" software on the device.I ordered a junker off Ebay,and fully updated it and snatched the firmware off that phone after about an hour of calculating all the partitions for a LUNS back up.You tell me what you need.I have all the V30 firmware on my backup drive and can send you just about anything you need.Oh,and the QueryListConfigs failed with Gobi error code: 16 (Malformed QMI response recieved) error is because you don't have the correct MBN files from the correct firmware on the device.Here's the V30 MBN files you need.It covers most all global carriers as I can see.
 

Attachments

  • V30 Modem MBN Files.zip
    636.1 KB · Views: 8
Last edited:

Zoki88

Senior Member
Feb 26, 2017
105
11
Zoki88 if you need the MBN files for the V30 I'll post them here.I have a full LUNS backup of the last firmware released for the AT&T V30 variant as well if you need it?I was true to my V30 when AT&T pulled their b.s. and wouldn't let the VoLTE work unless it had "their" software on the device.I ordered a junker off Ebay,and fully updated it and snatched the firmware off that phone after about an hour of calculating all the partitions for a LUNS back up.You tell me what you need.I have all the V30 firmware on my backup drive and can send you just about anything you need.Oh,and the QueryListConfigs failed with Gobi error code: 16 (Malformed QMI response recieved) error is because you don't have the correct MBN files from the correct firmware on the device.Here's the V30 MBN files you need.It covers most all global carriers as I can see.
Thing is that i already have in my phone a lot of mbn carrier files with device itself without my interfering to add any new, but problem is that i was trying to activate and deactivate lot of them, none of them would make IMS status registered, there's even mbn file for my actual carrier, but even that one doesn't make IMS status registered. I found out on lot of threads here that for lot of people in Europe carriers, including my Yettel carrier, Vodafone India mbn profile make it works perfectly, but those are said for OnePlus, Pixel, ROG, and Xiaomi devices, where people were actually able to put/load mbn in PDC from other devices that are not same device (only thing that is important is to be from device with same chipset). LG doesn't allow to put mbn from other devices, not even from same brand, only putting mbn from different variant of V30 works, which i tried some. My V30 actually have some Vodafone India mbn, which i immediately tried to activate it, still no IMS registered, so that Vodafone India mbn from any V30 isn't same as Vodafone India mbn from OnePlus 5 for example, or Pixel 2, and can't put that other ones in my device, so can't do much. It's mostly my carrier's fault for being so limited with devices which support VoLTE, even less than other Europe carriers. You can see on pic that i have a lot of mbn in system already, and will also put all mbn which my device default have, if anyone need it. But tysm for trying to help!
 

Attachments

  • V30 MBN.zip
    657.5 KB · Views: 6
  • Capture.JPG
    Capture.JPG
    111.3 KB · Views: 15

MarkFS33

New member
Aug 21, 2018
2
1
Fisrt of all, amazing tutorial and effort on do it, but I have a problem.

I have an Unlocked T-mobile V60, I tried to do the tutorial but when I connect the phone on the QMICM mode, it doesn't even show in the device manager nor make the Windows sound for a new connected device. When i return it to Android mode it pops right up as a "v60" and Windows makes the sound of connected device but on QMICM mode its just like it's not even connected.

Drivers are installed correctly but again, when I connect the phone it just doesn't shows up as nothing at all.

Any ideas?
 

surgemanx

Senior Member
Jan 29, 2022
172
31
Fisrt of all, amazing tutorial and effort on do it, but I have a problem.

I have an Unlocked T-mobile V60, I tried to do the tutorial but when I connect the phone on the QMICM mode, it doesn't even show in the device manager nor make the Windows sound for a new connected device. When i return it to Android mode it pops right up as a "v60" and Windows makes the sound of connected device but on QMICM mode its just like it's not even connected.

Drivers are installed correctly but again, when I connect the phone it just doesn't shows up as nothing at all.

Any ideas?
Try this driver,it should correct your problem.But,it won't correct the IMS issues with a T-Mobile device to work on AT&T if that's what you're trying.
 

Attachments

  • Qualcomm_USB_Driver_v1.0.zip
    19.5 MB · Views: 8
  • Like
Reactions: MarkFS33

MarkFS33

New member
Aug 21, 2018
2
1
Try this driver,it should correct your problem.But,it won't correct the IMS issues with a T-Mobile device to work on AT&T if that's what you're trying.
Thanks for the reply. I tried the driver but no luck. Again the phone charges but in Windows it's like i connect nothing. Tomorrow will try on another PC.

And I'm not looking to it to work on ATT, im outside USA, i'm in Mexico and I just wanna try luck to see if I can use VoLTE on any of the carriers here, currently I use a carrier on the "homologated" standard cellphone network in Mexico that uses band 17, but If VoLTE works on any other carrier here i will change to that
 
  • Like
Reactions: surgemanx

tlogan23

New member
Jan 24, 2008
4
0
BLU R1 HD
I'm gonna keep the intro simple, been a longtime user here on XDA, and recently I found that my T-Mobile LG G8 only supported VoLTE and VoWifi on, you guessed it, T-Mobile! So I did some research, experimented with my G8 for a bit, and I now have a method that works and does not need root at all. Basically, what we are doing here is just loading carrier profiles into the phone's modem so that the phone is able to complete IMS registration and correctly provision VoLTE when you insert a SIM card from another carrier.

If you are trying this on a LG V60, please turn off USB debugging before attempting this as multiple V60 owners have had trouble properly installing the modem driver and only resolved the driver issue by turning it off. Also, please try the 90E5 driver if the 9091 driver does not work for you.

This method does not work on the Sprint G8, any other Sprint LG devices, the Korean G8 and any other Korean LG devices since there is no Field Test option in the HiddenMenu in those devices.


Follow this post here, and make sure you read the original post in that thread as well. Also should work with other BL unlocked G8 models. Crossflash your G8 to Open US or Open CA firmware using this method! No unlocked bootloader or root needed!

DO THIS FIRST!!!!!: STEPS TO OBTAIN CARRIER MBN FILES FOR YOUR DEVICE (MBN files for the G8/G8x/G8s provided in Step 11 of the main guide)

1. Download a KDZ for your device. Sites like lgrom.com or lg-firmwares.com have KDZ's available to download. If you have an AT&T LG device just download a KDZ for another variant of your phone. Ex: If you have the AT&T LG Velvet, just download the Canadian Velvet's KDZ. Same for the AT&T G8, G8x etc.

2. Download and install
7zip, and the linked/attached KDZ extractor tool.

3. Extract the KDZ tool zip file, then place your downloaded KDZ into the same folder as the KDZ tools.

4. In the KDZ tools folder, find "OneKeyExtraction.bat" and double click on it.

5. When the CMD windows launches, press Y to start extracting the partitions from the KDZ.

6. Once it is finished, you should see a new folder in the KDZ tools folder that has the same name as the KDZ that you downloaded. Open up that folder.

7. As you can see the tool extracted all of the partitions that are contained in the KDZ file. We will need to open up either the modem_a or modem_b partitions to grab the needed MBN files. Scroll down to find those partitions. Doesn't matter which one you choose.

8. Right click on whichever one you chose, hover over "7zip", then click "Open archive".

9. 7zip will open up. The folders where the MBN's will be vary by device. Generally you should first look for a folder named "modem_pr", then once in it find the "mcfg_sw" folder. Here are some examples to help you find where the MBN files in your device's modem partition are. The files will be seperated into folders by region and carrier.



10. Once you find the files, extract them to whichever folder you want to.



Now here are the steps to load the MBN's:

1. Download the latest QPST Tools from here. Only runs on Windows. No Linux, sorry.

2. Extract the zip file you downloaded and open QPST.2.7.496.1.exe to install the QPST tools.


3. Once that is done, go to the Driver folder and open Qualcomm USB Driver V1.0.exe to install the drivers needed for the tool to communicate with your phone.

4. After that is done, there should be a QPST folder in your start menu. We'll come back to that later.

5. On your phone, go to the dialer and enter this code:
Code:
*#546368#*xxx# OR #*462633*#xxx# *xxx is the three numbers in your device's model code.

6. The HiddenMenu should pop up, choose Field Test, then LTE Data Test, and change the Tethering Mode from Android to QMICM. I recommend leaving your phone in this menu so that it is easier to switch back to the normal Android USB connection mode when you are done.


7. Connect your phone to your computer, it should be detected as "Qualcomm HS-USB Modem 9091". In Device Manager it should show up under the Modems section.

8. Go to the QPST start menu folder and open the "PDC" application.

9. Go to the Device dropdown, there should be an item named "Qualcomm Wireless HS-USB Ethernet Adapter 9091". This is your phone, select it.
10. This is what you should see. Notice how only the original carrier's (T-Mobile) modem profile is loaded into the phone's modem. Pretty lazy if you ask me.
11. Now you will need some modem profiles to load into your phone! As a little starter pack, here are a few carrier modem profiles for US, Canadian and Korean carriers. Download them here (these are only for the G8/G8x/G8s! Will not work with other devices!!!!!!). I have extracted these from my phone's modem_a partition using QFIL Partition Manager with the LG SD855 firehose, and these are present in the modem_b partition as well. LG left all of these profiles inside the phone but only actually loads one of them into the modem on carrier models....

These profiles may also work on the G8x, V50, and G8s since those phones have the same SOC as the G8, and by extension the same modem chip.

12. Once you are ready, press the Load button and navigate to whichever carrier profile you want to add, I will load AT&T as an example. After going inside the folder for the carrier you want to load, there should be a file named "mcfg_sw.mbn". This is the profile. Don't bother adding any profile that has "row" in it's name, those usually don't give you support for VoLTE.
13. When you are ready, click Open and your carrier profile will be loaded into your phone! You can go and add as many carriers as you want, I loaded all US and Korean, and some Canadian carrier profiles into my G8.

Do not load the same profile multiple times, this may cause issues with VoLTE and cell connectivity.

14. When you are done, go back to the LTE Data Test menu and set the tethering mode back to Android. Your phone now has VoLTE support for the carriers that you loaded into it!

If you have another Qualcomm LG device, you can also follow this guide, you just need to enter the HiddenMenu dialer code specific to your device, and have carrier config files that are either specifically for your device, or from another phone that has the same chipset as your device* (*may or may not work).

Here's AT&T VoLTE working with a Tracfone AT&T sim card on my previously incompatible T-Mobile G8:

Hope this guide has helped you guys!
Thank you, it worked like a charm on my ATT unlocked LG G8 ThinQ using Consumer Cellular. Consumer Cellular support got my phone service back, but the only way I could get Data, was to switch to the CC APN, but then I lost phone service. Liked the fact that I didn't have to root and wander the endless ROM maze to fix the problem or trying to cross-flash to a generic LG. Thank you again. For those of you who are thinking of doing this. Make sure you do Wish39 tells you to do!
 

surgemanx

Senior Member
Jan 29, 2022
172
31
Thank you, it worked like a charm on my ATT unlocked LG G8 ThinQ using Consumer Cellular. Consumer Cellular support got my phone service back, but the only way I could get Data, was to switch to the CC APN, but then I lost phone service. Liked the fact that I didn't have to root and wander the endless ROM maze to fix the problem or trying to cross-flash to a generic LG. Thank you again. For those of you who are thinking of doing this. Make sure you do Wish39 tells you to do!
It works because it actually updated OTA.Consumer Cellular is an MVNO of AT&T.
 

Kelpe1925

New member
Apr 18, 2021
3
0
LG V60 ThinQ
Ok, so I went through all your processes with the same phone as you and used your files for my ATT G8 and it did not work. Like someone else said, it now shows that my TMO is active and says I'm connected, instead of disconnected... but it did nothing to change the fact that I cannot provision my Volte to turn on, I'm guessing due to something in ATT's software. Looks like unless I'm going to try and cross-flash, that there is no actual way to do this easy.

Wasted a good part of a day on this... so if you have anything else I can try, I'll probably do it.
 
Last edited:

Wish39

Senior Member
Jan 13, 2015
196
48
Ok, so I went through all your processes with the same phone as you and used your files for my ATT G8 and it did not work. Like someone else said, it now shows that my TMO is active and says I'm connected, instead of disconnected... but it did nothing to change the fact that I cannot provision my Volte to turn on, I'm guessing due to something in ATT's software. Looks like unless I'm going to try and cross-flash, that there is no actual way to do this easy.

Wasted a good part of a day on this... so if you have anything else I can try, I'll probably do it.
Try this:
1. Create a new folder in your internal storage named "enable_ue"
2. Dial #546368#*820
3. Go into field test==>universal enabler
4. Click "Create New Config"
5. Then enable all 4 boxes and see if VoLTE will work

If this doesn't work then flashing Open US G820QM firmware is the only solution for you to get T-Mobile VoLTE support.

Saw your reddit post, for the Mint APN leave the MNC as 240, Mint sim cards are MCC 310 MNC 240, not 310 260 like actual T-Mobile sim cards. This is why it disappears when you try to save it with the MNC as 260.
 
Last edited:
  • Like
Reactions: surgemanx

Top Liked Posts

  • There are no posts matching your filters.
  • 1
    Ok, so I went through all your processes with the same phone as you and used your files for my ATT G8 and it did not work. Like someone else said, it now shows that my TMO is active and says I'm connected, instead of disconnected... but it did nothing to change the fact that I cannot provision my Volte to turn on, I'm guessing due to something in ATT's software. Looks like unless I'm going to try and cross-flash, that there is no actual way to do this easy.

    Wasted a good part of a day on this... so if you have anything else I can try, I'll probably do it.
    Try this:
    1. Create a new folder in your internal storage named "enable_ue"
    2. Dial #546368#*820
    3. Go into field test==>universal enabler
    4. Click "Create New Config"
    5. Then enable all 4 boxes and see if VoLTE will work

    If this doesn't work then flashing Open US G820QM firmware is the only solution for you to get T-Mobile VoLTE support.

    Saw your reddit post, for the Mint APN leave the MNC as 240, Mint sim cards are MCC 310 MNC 240, not 310 260 like actual T-Mobile sim cards. This is why it disappears when you try to save it with the MNC as 260.
    1
    I noticed this when I upgraded to android 12 EA firmware. The QMICM mode doesn't show up in device manager or show any sign. But I downgraded to TM android 11 Firmware and it works. I don't know if this is a bug or they've patched it on Android 12. If anyone on Android 12 got it to work please let us know.
    LG either unintentionally or intentionally broke the QMICM mode in Android 12, need to update the guide to include that info. Same behavior on my AT&T Velvet with Android 12.
  • 9
    This guide will not work if you are running Android 12 :(

    I'm gonna keep the intro simple, been a longtime user here on XDA, and recently I found that my T-Mobile LG G8 only supported VoLTE and VoWifi on, you guessed it, T-Mobile! So I did some research, experimented with my G8 for a bit, and I now have a method that works and does not need root at all. Basically, what we are doing here is just loading carrier profiles into the phone's modem so that the phone is able to complete IMS registration and correctly provision VoLTE when you insert a SIM card from another carrier.

    If you are trying this on a LG V60, please turn off USB debugging before attempting this as multiple V60 owners have had trouble properly installing the modem driver and only resolved the driver issue by turning it off. Also, please try the 90E5 driver if the 9091 driver does not work for you.

    This method does not work on the Sprint G8, any other Sprint LG devices, the Korean G8 and any other Korean LG devices since there is no Field Test option in the HiddenMenu in those devices.


    Follow this post here, and make sure you read the original post in that thread as well. Also should work with other BL unlocked G8 models. Crossflash your G8 to Open US or Open CA firmware using this method! No unlocked bootloader or root needed!

    DO THIS FIRST!!!!!: STEPS TO OBTAIN CARRIER MBN FILES FOR YOUR DEVICE (MBN files for the G8/G8x/G8s provided in Step 11 of the main guide)

    1. Download a KDZ for your device. Sites like lgrom.com or lg-firmwares.com have KDZ's available to download. If you have an AT&T LG device just download a KDZ for another variant of your phone. Ex: If you have the AT&T LG Velvet, just download the Canadian Velvet's KDZ. Same for the AT&T G8, G8x etc.

    2. Download and install
    7zip, and the linked/attached KDZ extractor tool.

    3. Extract the KDZ tool zip file, then place your downloaded KDZ into the same folder as the KDZ tools.
    1646120728815.png

    4. In the KDZ tools folder, find "OneKeyExtraction.bat" and double click on it.

    5. When the CMD windows launches, press Y to start extracting the partitions from the KDZ.

    6. Once it is finished, you should see a new folder in the KDZ tools folder that has the same name as the KDZ that you downloaded. Open up that folder.
    1646121613132.png

    7. As you can see the tool extracted all of the partitions that are contained in the KDZ file. We will need to open up either the modem_a or modem_b partitions to grab the needed MBN files. Scroll down to find those partitions. Doesn't matter which one you choose.

    8. Right click on whichever one you chose, hover over "7zip", then click "Open archive".
    1646122181314.png

    9. 7zip will open up. The folders where the MBN's will be vary by device. Generally you should first look for a folder named "modem_pr", then once in it find the "mcfg_sw" folder. Here are some examples to help you find where the MBN files in your device's modem partition are. The files will be seperated into folders by region and carrier.
    1646122816648.png

    1646122875662.png

    1646122958551.png

    10. Once you find the files, extract them to whichever folder you want to.



    Now here are the steps to load the MBN's:

    1. Download the latest QPST Tools from here. Only runs on Windows. No Linux, sorry.

    2. Extract the zip file you downloaded and open QPST.2.7.496.1.exe to install the QPST tools.

    1633495073816.png

    3. Once that is done, go to the Driver folder and open Qualcomm USB Driver V1.0.exe to install the drivers needed for the tool to communicate with your phone.

    4. After that is done, there should be a QPST folder in your start menu. We'll come back to that later.

    5. On your phone, go to the dialer and enter this code:
    Code:
    *#546368#*xxx# OR #*462633*#xxx# *xxx is the three numbers in your device's model code.

    6. The HiddenMenu should pop up, choose Field Test, then LTE Data Test, and change the Tethering Mode from Android to QMICM. I recommend leaving your phone in this menu so that it is easier to switch back to the normal Android USB connection mode when you are done.

    1633495857477.png
    1633495872107.png
    1633495890722.png

    7. Connect your phone to your computer, it should be detected as "Qualcomm HS-USB Modem 9091". In Device Manager it should show up under the Modems section.

    8. Go to the QPST start menu folder and open the "PDC" application.

    9. Go to the Device dropdown, there should be an item named "Qualcomm Wireless HS-USB Ethernet Adapter 9091". This is your phone, select it.
    1633496853860.png
    10. This is what you should see. Notice how only the original carrier's (T-Mobile) modem profile is loaded into the phone's modem. Pretty lazy if you ask me.
    1633497146862.png
    11. Now you will need some modem profiles to load into your phone! As a little starter pack, here are a few carrier modem profiles for US, Canadian and Korean carriers. Download them here (these are only for the G8/G8x/G8s! Will not work with other devices!!!!!!). I have extracted these from my phone's modem_a partition using QFIL Partition Manager with the LG SD855 firehose, and these are present in the modem_b partition as well. LG left all of these profiles inside the phone but only actually loads one of them into the modem on carrier models....

    These profiles may also work on the G8x, V50, and G8s since those phones have the same SOC as the G8, and by extension the same modem chip.

    12. Once you are ready, press the Load button and navigate to whichever carrier profile you want to add, I will load AT&T as an example. After going inside the folder for the carrier you want to load, there should be a file named "mcfg_sw.mbn". This is the profile. Don't bother adding any profile that has "row" in it's name, those usually don't give you support for VoLTE.
    1633498811451.png
    13. When you are ready, click Open and your carrier profile will be loaded into your phone! You can go and add as many carriers as you want, I loaded all US and Korean, and some Canadian carrier profiles into my G8.

    Do not load the same profile multiple times, this may cause issues with VoLTE and cell connectivity.
    1633501377502.png

    14. When you are done, go back to the LTE Data Test menu and set the tethering mode back to Android. Your phone now has VoLTE support for the carriers that you loaded into it!

    If you have another Qualcomm LG device, you can also follow this guide, you just need to enter the HiddenMenu dialer code specific to your device, and have carrier config files that are either specifically for your device, or from another phone that has the same chipset as your device* (*may or may not work).

    Here's AT&T VoLTE working with a Tracfone AT&T sim card on my previously incompatible T-Mobile G8:
    1633502003068.png
    1633502017259.png

    Hope this guide has helped you guys!
    1
    If it's anything like the Sprint V50, see if 5689#*820# works. But I suspect that even if it works, there won't be a Field Test option.
    Yeah, same result.

    If I use *#*#7262626#*#*, upon pressing the last * the code disappears and I'm still on the dialer.

    1
    Its weird, as far as I can tell... my device has VoLTE enabled on Tmobile, eventhough its DEFINITELY a Sprint model. Aside from that, I use Google Voice, which essentially lets me make calls and use data at the same time anyway.
    1
    On my Sprint G8X on 20p, simply replacing abl_a and abl_b with the special one used for BL unlocking made my phone think it's a T-Mobile one and enabled Field Test in the HiddenMenu. It's not necessary to do the BL unlock itself if you don't need it. Just thought I'd mention it in case anyone wants to try this on a Sprint phone.
    1
    That's too bad, but makes sense since the abl came from an 850.
    I wonder if you can use abl files from a different branded or unbranded V50? I'd think if you're not planning to BL unlock, you wouldn't need it to be an engineering abl.
    Looks like it's unfortunately still a no-go for the Sprint V50.

    Even after putting in the engineering abl file to make it look like an LM-G850, the 546368 dialer code still doesn't work (tried 850, 450, 820, 500 for model numbers) while the Sprint alternative code 5689#*850# still gives the same options as out-of-the-box with no Field Test.

    So I guess unlocking the bootloader and root access (to replace op partition files after which the 546368 code will work) are still needed for this particular model.

    Just to clarify, it's whats in the OP partition that will (or won't) allow those dial codes to work. And yes, the engineering abl, being from a specific model / variant of android, will almost always mean the device won't boot when it's flashed to the abl partition.

    So, if yours booted with it, and it seemed to somehow allow additional dial codes to work, then your OP partition somehow got the message it was a different variant device, and made them available. That's unusual, quite rare. Trying to repeat that with various other abl partitions from other devices / android versions is almost guaranteed to be a futile endeavor.

    The best way to do this, as mentioned, is to use the US open OP partition, and make sure the totc file is set to your specific variant (of course). Then the phone will act / be much like the US Open variant does, have volte and vowifi, less bloat, etc.

    But to get to that point, yes, bl unlocked and root / twrp needed.

    cheers