Hello! I need help with the USSD requests from my modem. I’m sending a request, but there’s no response. Everything works with this SIM card and phone (or a modem from another manufacturer). How can I solve this? at+cusd=1,*205# at+cusd=1,*205# OK ati ati Manufacturer: Sierra Wirel…

how about using newer firmware? at+cusd=1,"*121#" OK +CUSD: 5,"*bHÇ3",0 ati3 Manufacturer: Sierra Wireless, Incorporated Model: MC7455 Revision: SWI9X30C_02.38.00.00 rE3F3E55C03AE94 jenkins 2022/01/13 05:16:00 MEID: 35907206012345 ESN: 12800003752, 80000EA8 IMEI: 359072060012345 IMEI SV: 22 FSN: L…

Hello! Thank you for your reply. I updated the firmware, but the result hasn’t changed. ati3 ati3 Manufacturer: Sierra Wireless, Incorporated Model: MC7455 Revision: SWI9X30C_02.38.00.00 rE3F3E55C03AE94 jenkins 2022/01/13 05:16:00 IMEI SV: 22 FSN: LQ621504330310 +GCAP: +CGSM OK >>> a…

I have no idea about this. can you change another SIM card with another network operator and see if it works?

I’ve already done this; both SIM cards from different operators work in EP06 and send USSD and receive a response. Any ideas? I have about 100 mc7455 modems and would really like to receive information. This is important to us.

have you contacted distributor? (please note that this module has been end of life for nearly three years, so there will not be any new firmware for fixing bugs)

I don’t think it can help better than official support.

ok, then you can contact for official support

Could there have been radical changes in 3GPP and the way USSD works in three years? I’m not really aware of this; I’m just starting to understand these issues.

i am not sure about this But i saw other user can make it work with MC7304: [image] No USSD responses MC/EM Series Hi Alex, I have tried on multiple networks & RATs with different SIM cards. Yes the SIM is registered and I can make calls. Thanks for any hel…

[image] jyijyi: i am not sure about this But i saw other user can make it work with MC7304: If you have MC7304, you can try with your SIM card Thanks for helping me figure this out. I have a lot of mc7304, and they all have the same problem. I haven’t updated the firmware on them yet becau…

MC7455 USSD not working

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jyijyi January 5, 2026, 8:50am 15

then seems to be network dependent as other user can make it work in other network

Btw, is your module ok to receive or send sms?

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MC7455 USSD not working

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