@progastar​ Yes exactly! Dell 5480 and 5490 SSD perfectly working in WWAN slot,But Dell7480 works one boot time after bios defult.

What is the solution?Anybody? 

As far as I've read here, this is no longer possible.  I too had an E7440 and it was definitely possible install an mSATA SSD into the mPCIe slot that could also accept a WWAN card.  The new systems use M.2/NGFF slots.  I don't believe they have SATA wiring to them, and even if you wanted to use an NVMe/PCIe SSD figuring that the WWAN slot certainly has PCIe wired to it, my understanding is that it's not enough for a slot to just have PCIe lanes wired to it in order to run an NVMe SSD.  It has to specifically support NVMe on that interface, and I don't believe the 7480 does on the WWAN slot.

I installed a second HDD (Transcend MTS 400) in the WWAN-Slot but there were some issus:

- booting => device was not visible
- booting (F2, load BIOS-defaults) => device ist visible on next boot
- booting => device is lost again

So the device is only visible once (and usable) directly after loading BIOS-defaults, after reboot it's lost (without changing the BIOS values). When I booted with BIOS-defaults, I was even able to install Windows, but it won't boot, because there is no boot option in UEFI.
Even the SSD is visible with BIOS-defaults in Windows, it is never shown in BIOS->"General->System Information".

My former 7440 was able to manage two SSD's without any problem. I can't understand this downgrade by Dell-developers.

So even as a secondary drive it was unusable as the drive was not visible to the OS booted of the primary SSD? I'm really looking for an option to add a secondary storage option to my 7480.

So I know this works with the Latitude E7240 using two mSATA drives - as I have tested this in the past.

But now, I have two other Dell laptops where I am trying to do this...a Latitude E7270 and a Latitude 7480.

On the E7270: I have a SATA 2280 SSD in the regular slot. I put a 2242 NVMe in the WWAN slot and although it does NOT show in BIOS, it does show in my native OS (which boots Windows 8.1 Enterprise 64-bit from the 2280).

I will do some testing with the 7480 and post here in a few days.

I know this is an old thread but I want the details here for future searches...

Replying to my post above: After testing in the Latitude 7480, I could not get the 2242 NVMe SSD to be recognized in Windows as a secondary drive like I could with the Latitude E7270...even though they both share the same drive/OS configuration (a 2280 SATA SSD in the main slot booting Windows 8.1 Enterprise). Both are running 6th-generation Intel processors (Core i5-6300U in the E7270 and a Core i7-6650U in the 7480)

If I manage to figure it out, I will post here.

Something new?????

I have literally tried EVERTHING to get the 2242-size NVMe working in the WWAN slot on the Latitude 7480 and unfortunately nothing works. I have tried going to older BIOS versions, tried every combination of settings in BIOS and Windows drivers...nothing. Really annoying. I've spent 10+ hours over several days trying...I know the system inside and out and have 15+ years in the field...and I am finally giving up on the 7480

Sorry gents...if anyone figures it out please let me know. I hate Win10 so I am sticking with my 6th-gen Corei7 Latitude 7480 until 2023 when Win8.1 Enterprise support ends. I'd love if someone can figure this out

Just try it the other way round:

- install the NVMe in the native M.2 NVMe slot
- install OS
- install your M.2 SSD (not an NVMe!!!) to the WWan slot.

This setup works for me

Best regards

Peter