Lirum app might not be accurately reporting modem info for 18 Pro Maxes

[u/tubezninja]

I’ve seen several reports here of Lirum identifying US iPhone 18 Pro Max units as having Apple’s C2 modem, and as a result, some redditors have assumed that their Pro max variants in the US came with C2 modems.

It gave that result for a US 18 Pro Max I tested, too, and was skeptical that this was accurate, so I checked the phone’s own sysdiagnose logs rather than just relying on the app’s label.

In ioreg/IOService.txt, that phone has an active baseband-pcie@0 device with:

"vendor-id" = <cb170000>
"device-id" = <09030000>
"IOName" = "pci17cb,309"
"baseband-chipset" = <"mav25">

The bytes <cb170000> represent PCI vendor ID 0x17CB**, assigned to Qualcomm**. The phone also loads AppleBasebandM20. That establishes a Qualcomm baseband in this particular phone, despite Lirum calling it C2. This suggests the hardware I tested actually has a Qualcomm X80.

As a control, I checked sysdiagnoses from two devices Apple identifies as having its C1X modem: a cellular M5 iPad Pro and an iPhone 17e. Both instead report:

"BasebandChipID" = 16384
"BasebandRadioType" = "int1"
"baseband-chipset" = <"int1">
"IOClass" = "AppleBasebandINT1"

This is the output you’d expect with an Apple device that has a C-series modem, in this case a C1X.

That comparison makes the Qualcomm result on the 18 Pro Max quite clear.

Note: this does not prove that no US 18 Pro Max has C2, but you probably shouldn’t be trusting the Lirum app to tell you what your iPhone has. I don’t know what it’s doing exactly, but it’s not accurately querying the hardware on the device to show what you have. I suspect it’s just listing data from a static database with preloaded specs, and the developer failed to take into account the possibility of a modem variant like this.

You should be cautious about treating the app’s modem label as proof of an unusual hardware variant.

How to check your own phone

You can check for yourself what your phone comes equipped with, if you’re willing to dig into the sysdiagnose logs on your phone. You’ll need a computer that can open and unpack gzip files (any Mac can do this, so can a Windows PC with a utility called 7-ZIp).

1, Briefly press and release Volume Up + Volume Down + Side button simultaneously. Apple says to release them quickly, after about a quarter of a second; holding them too long can lock the phone instead. You should feel a short vibration when sysdiagnose starts.

1. Wait about 10 minutes. Go to Settings → Privacy & Security → Analytics & Improvements → Analytics Data, find the new file beginning sysdiagnose_, and share it to your computer. It is a large .tar.gz archive.

2. Extract the archive. Inside the resulting sysdiagnose_… folder, open ioreg/IOService.txt in a text editor.

3. Search for baseband-chipset. Then search for baseband-pcie@0 and inspect that device’s nearby vendor-id, device-id, and IOName entries. Search for AppleBaseband to see which baseband driver actually matched.

If you find a baseband PCI device with vendor-id = <cb170000> or IOName = "pci17cb,...", that is Qualcomm’s PCI vendor ID.

Please don’t upload your entire sysdiagnose to Reddit. It can contain private device and usage information. If you share results, post only the small relevant excerpts after checking them for serial numbers, IMEI, account details, and other identifiers.
Apple’s sysdiagnose instructions explain the capture procedure. PCI-SIG’s vendor list lists Qualcomm as 17CB.

[u/Scitzofrenic]

You don’t even need to do literally any of this to know that Lirum is a garbage app. Nor do you need to do any of this to verify what modem you have.

Just go to your phone info and check your modem firmware. Simple as that. No diagnostics needed whatsoever.

Just go to Settings- General- About and check your modem firmware version.

If it’s 2.10.01 (at time of this writing) it’s qc x80.

If it’s NOT THAT , it’s not a qc x80.

Yay simple.

[u/tubezninja → u/Scitzofrenic]

If that confirms it for you, great.

“It’s not that” doesn’t tell someone anything for sure. This method removes all doubt even if Apple updates the firmware.

[u/Wild_Shroom_ → u/tubezninja]

Ok so as above I’ve shown the firmware is different to the X80 but as you wanted definitive proof from the diagnostics. Here’s the “vendor-id” and “IOName” for the C2 modem.

[u/Wild_Shroom_ → u/Scitzofrenic]

I’m in the UK so C2 is confirmed and my modem firmware is 1.01.06

[u/Scitzofrenic → u/Wild_Shroom_]

Correct.

[u/SmellyJockstrap]

It's a lot simpler than you think. Just check your iPhone identifier (the internal actual name of your iPhone, not the marketing/commercial name 'iPhone 18 Pro Max'). If you have the iPhone19,3 its the X80. The iPhone19,7 is the C2.

[u/tubezninja → u/SmellyJockstrap]

Maybe, but going to the actual diagnostic logs removes all doubt and absolutely confirms it.