SIM2 not working on EM7590

I wanted to test access to SIM1 and SIM2 of a new EM7590 (FW SIM1 ok, SIM2 no access, AT+CPIN? says “CME ERROR: SIM busy”.
Verified with AT!CUSTOM? that UIM2ENABLE=1, switched to SIM2 with AT!UIMS=1.
Updated Firmware to latest, did not change.
Testplatform Techship adapter MU201, same on own platform with M.2 key B socket.
Same test passes ok for both SIM slots with EM7455 and EM7565.
Is this an internal restriction of the EM7590?
Thanks for any help!

Manufacturer: Sierra Wireless
Model: EM7590
Revision: SWIX12C_01.01.07.00 2022/11/14 16:14:31
SVN: 02
IMEI: 357999720004136
FSN: 01225200097A20


Hi @urban
Welcome you to our community
Could you please share with me some information as below:

  1. Have you install the latest driver on source page Sierra? If no, Please install the latest driver following the link below:
  2. Can you try another SIM to see if the issue still happens?
  3. Please share with me the output of command AT+CCID
  4. Are you using Sierra board or custom board? If you are using custom board, Please try using the Sierra board. Do the issue still happens in this case?


Hi @jerdung

  1. Yes, I have installed the latest drivers 7590.1008.000 from the Sierrawireless website.
  2. It does not depend on the SIM, we tried several. It even happens when there is no SIM in the second slot: “SIM busy” instead of “SIM not inserted”.
  3. The AT+CCID command returns “Error”, it is not listet in the EM7590 AT Command Reference Doc, so I guess it is not supported.
  4. We are using the Techship adapter MU201 as well as our own platform. Both show the same behaviour, with Windows 11 and also with Linux Ubuntu 22.04 LTS. We do not have a Sierra board.
    Does the EM7590 has something internal connected to the second SIM interface?


Hi @urban ,
So, for this case, in order to determine I think it’s better to try your EM7590 module on the Sierra board.


Hi @jerdung,
As I explained, we do not have a Sierra board available. But the issue is not dependent on the carrier board. The EM7455 and EM7565 can operate the second SIM without any problem on the same carrier board. It is an internal issue of the EM7590 only.
Do you have an EM7590 to verify the issue?


I don’t have any EM7590 so I could be wrong., but I believe this is as documented in the PTS. Isn’t it? At least it is in the revision I had laying around. The UIM2 pins are used for mmWave antenna management on the EM9190, and I assume the pins therefore are reserved on the EM7590 and EM9191 too.

The documented SIM2 option is an optional eSIM on these modules.

Hi @dl5162,
In which version of EM7590 PTS did you find this information? I checked the latest (revision 5) and did not find anything about UIM2 pins not usable for a SIM interface.


Apologies. I was rechecking this now and noticed my error: EM7590 != EM7690. I was confusing your module with the EM7690.

I know nothing about the EM7590. Wasn’t even aware it existed. Sorry for the confusion

No problem, thanks for helping!

Hi @jerdung,
Do you have any news from Sierra Wireless about this issue?

Hi @urban
In case you test on the same board, the test passes with both the EM7455 module and the EM7565 module, but the test fails with the EM7590 module. So, I think it’s better to raise this kind of issue via email tech support: for further deeper support.


Hi @jerdung,
Thanks, I’ll do that.

Sierra Wireless says: “The first PV samples have been populated with a consumer eSIM, which prevents using SIM2. For SKU 1105039 MP orders, the eSIM will be depopulated, so external SIM can be used on SIM2 interface.”
Unfortunately also the first 1105039 MP order we just received behaves the same… :disappointed:

With the latest MP order SIM2 now is supported correctly. SKU stays the same.