Ec25, at+cusd cme error: 258

Hello guys,

I have a problem with getting my phonenumber with USSD-Code in 4G modem with Quectel EC25 Chip (EC25-EC or EC25-EUX) and I hope you can help me.

First of all some basic informations:

Its a german SIM card (provider: fonic) and I am using it in the Czech Republic, the USSD-Code is *#62#. And I don’t know why, but everytime I get the error code “+CME ERROR: 258”.

When I use the same card in 2G modem with Quectel M26 Chip the USSD-Code works fine without any problems.

I had also problems with other SIM cards (different providers like Lebara or Lycamobile, also from Germany), but I could solve them by using following AT Commad:

Step 1:
AT+CSCS=“GSM”

Step 2:
AT+QURCCFG=“urcport”,“uart1”

Unfortunately it don’t help with fonic card in new modem (EC25 Chip).

4G Modem:

Sending AT query…
AT

OK
Successfull response for AT query…

Enabling echo and verbose mode
ATE1V1

OK
AT+CGMM

EC25

OK
Model Number : EC25
AT+CGMI

Quectel

OK
Manufacturer : Quectel

AT+CSCS=“GSM”
OK
AT+QURCCFG=“urcport”,“uart1” (also tried with “all”,“usbmodem” and “usbat” - same results)
OK
AT+CUSD=1,"*#62#",15
OK

+CME ERROR: 258

AT+COPS?
+COPS: 0,0,“O2 - CZ”,0

OK

AT+CREG?
+CREG: 0,5

OK

Thank you for your time and your help!

Kind regards
Eddy

i had the same problem, if connect to GSM network it works fine, but when come to LTE network it keep Erro30, CME error: No network service

Hope some one could help.

For most (and perhaps all) providers, USSD works only on 2G and 3G networks.

So but how is it possible with other SIM cards (other providers). Maybe the not working card is trying to connect to LTE, maybe there is a possibility to stop connecting to LTE network and instead connecting to 2G or 3G?

If the modem is in auto mode for RAT selection (2G, 3G, 4G), it should drop back from 4G to 3G (or 2G) automatically to execute an AT+CUSD command.

If the modem is set to 4G-only, or if 4G is the only RAT available at the location, then the AT+CUSD command won’t work.

Hey snowgun, what is the RAT selection and which command i need to change it?

i am curious about the USSD when we are using under 4G network. Cause we can get the respond from 4G network.

it could not be, cause we have some country was totally shut down for 2G network.

AT+QCFG="nwscanmode" reads the current configuration. Interpretation of returned values:

0 - Automatic
1 - 2G/GSM only
2 - 3G/WCDMA only
3 - 4G/LTE only

To set to 3G/WCDMA-only, for example, the command is AT+QCFG="nwscanmode",2

I’m not aware of any provider who has implemented USSD over 4G. I guess it’s possible. But for most people, USSD would work because of an automatic fall-back to 3G for the duration of the USSD session.