EC25-E SIM Registration Failed (GSM/VoLTE)

ilyasahmad · January 20, 2026, 3:07pm

Hi,

I am using the EC25-E module and are facing a SIM registration issue on one particular module, while the same SIM works properly on another EC25-E module running the same firmware version.

Observations:

The SIM is confirmed to be working
Firmware version is identical on both modules
SIM registration issue is observed only on one specific EC25-E module
Other EC25-E modules with the same firmware are registering the SIM without any issue

Possible checks already considered:

SIM is tested on another module and works fine
Same issue with the other operator’s SIM

Could you please help us understand:

Whether this could be related to RF/antenna performance, IMEI issues, or module hardware degradation
If there are any specific AT commands or NV parameters we should verify
If the issue could be related to network band lock, SIM interface, or signal sensitivity
Any known issues where a module fails SIM registration even with identical firmware

I have attached the AT command outputs for your reference to assist in further analysis.

Looking forward to your technical guidance and recommended troubleshooting steps.

AT Commands output:-

NORMAL POWER DOWN
POWERED DOWN
RDY
+CFUN: 1
+CPIN: READY
+QUSIM: 1
ATE1
OK
ATE1
OK
AT+GMM
EC25
OK
AT+CPIN?
+CPIN: READY
OK
AT+CMGF=0
OK
AT+CLIP=1
OK
AT+CREG=2
OK
+QIND: SMS DONE
AT+CGREG=2
OK
AT+GMR
EC25EFAR06A06M4G
OK
AT+COLP=1
OK
AT+CNMI=2,2,0,0,0
OK
AT+CLVL=4
ERROR
AT+QMIC=12000,12000
ERROR
at+qaudcfg=“alc5616/ulgain”,12
ERROR
+CREG: 0
+CGREG: 0
at+qaudcfg=“alc5616/dlgain”,75
ERROR
AT+QSIDET=0
ERROR
AT+CSCS=“UCS2”
OK
AT+QENG=1,1
ERROR
AT+CPIN?
+CPIN: READY
OK
AT+CIMI
405664620961770
OK
+QIND: PB DONE
AT+CGREG?
+CGREG: 2,0
OK
AT+CGREG?
+CGREG: 2,0
OK
AT+CSQ
+CSQ: 25,99
OK
AT+EGMR=0,7
+EGMR: “866758044582241”
OK
AT+CSQ
+CSQ: 25,99
OK
AT+EGMR=0,7
+EGMR: “866758044582241”
OK
AT+QNWINFO
+QNWINFO: “TDD LTE”,“40411”,“LTE BAND 8”,40940
OK
AT+CGREG?
+CGREG: 2,0
OK
AT+QMBNCFG=“list_all”
+QMBNCFG: “List_all”,0,0,0,“ROW_Generic_3GPP”,0x05010824,201806201,“”
+QMBNCFG: “List_all”,1,0,0,“Reliance_OpnMkt”,0x05011B4B,201801051,“405-840”
+QMBNCFG: “List_all”,2,1,1,“Reliance_India_VoLTE”,0x05800202,000000000,“405-874”
OK
AT+CREG?
+CREG: 2,0
OK
AT+CGREG?
+CGREG: 2,0
OK
AT+QMBNCFG=“AUTOSEL”
+QMBNCFG: “AutoSel”,0
OK
AT+QCFG=“nwscanseq”
+QCFG: “nwscanseq”,0403010502
OK
AT+QCFG=“nwscanmode”
+QCFG: “nwscanmode”,3
OK
AT+QCFG=“BAND”
+QCFG: “band”,0x93,0x180000000fd,0x0
OK
AT+QGMR
EC25EFAR06A06M4G_01.006.01.006
OK
ATI
Quectel
EC25
Revision: EC25EFAR06A06M4G
OK
AT+QENG=“servingcell”
+QENG: “servingcell”,“LIMSRV”,“LTE”,“FDD”,404,11,71A7B16,160,1421,3,3,3,CE31,-81,-9,-55,13,42
OK
AT+CREG?
+CREG: 2,0
OK
AT+CGREG?
+CGREG: 2,0
OK
AT+CSQ
+CSQ: 28,99
OK
AT+QCFG=“ims”
+QCFG: “ims”,0,0
OK
AT+QCSQ
+QCSQ: “LTE”,57,-82,172,-8
OK
AT+COPS=?
+COPS: (0,“IN-DOLPHIN”,“DOLPHIN”,“40468”,2),(0,“Vodafone IN”,“Vodafone”,“40411”,0),(0,“IND airtel”,“airtel”,“40410”,0),(0,“Vi India”,“Vi India”,“40411”,7),(0,“IND-JIO”,“JIO”,“405872”,7),(0,“IND airtel”,“airtel”,“40410”,7),(0-4),(0-2)
OK
AT+QNWINFO
+QNWINFO: “FDD LTE”,“40411”,“LTE BAND 3”,1421
OK
AT+CGDCONT?
+CGDCONT: 1,“IPV4V6”,“”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 2,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 3,“IPV4V6”,“SOS”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,1
OK
AT+QENG=“neighbourcell”
+QENG: “neighbourcell intra”,“LTE”,40940,429,-9,-92,-62,-20,31,7,14,8,44
+QENG: “neighbourcell inter”,“LTE”,3601,-,-,-,-,-,-,0,12,5
+QENG: “neighbourcell inter”,“LTE”,1421,-,-,-,-,-,-,0,12,6
OK
AT+CEREG?
+CEREG: 0,0
OK
AT+CGACT?
+CGACT: 1,0
+CGACT: 2,0
+CGACT: 3,0
OK
AT+GSN
866758044582241
OK

AmarRaaj · January 21, 2026, 3:18am

Hi ilyasahmad,

The most likely cause is a conflict between the active MBN file and the network you are trying to join.

Based on the AT logs you provided:

Active Cell: AT+QENG=“servingcell”

AT+QENG=“servingcell”
+QENG: “servingcell”,“LIMSRV”,“LTE”,“FDD”,404,11,71A7B16,160,1421,3,3,3,CE31,-81,-9,-55,13,42
OK

it shows the module is camping on Vodafone IN (PLMN 404-11)

However when looking at the MBN AT command

AT+QMBNCFG=“list_all”
+QMBNCFG: “List_all”,0,0,0,“ROW_Generic_3GPP”,0x05010824,201806201,“”
+QMBNCFG: “List_all”,1,0,0,“Reliance_OpnMkt”,0x05011B4B,201801051,“405-840”
+QMBNCFG: “List_all”,2,1,1,“Reliance_India_VoLTE”,0x05800202,000000000,“405-874”

It shows the module had the “Reliance_India_VoLTE” MBN activated (PLMN 405-874) and that “AutoSel” was disabled.

Because the module is forced to use Reliance Jio parameters while trying to register on a Vodafone cell, the network registration is being rejected

Recommendation:

Enable MBN Auto-Selection
This allows the module to automatically load the correct settings when it detects the SIM card

AT+QMBNCFG=“AutoSel”,1

Clear Stored Location Information
If the module is trying to use invalid stored data (RPLMN), clear it to force a full system scan.

AT+CRSM=214,28643,0,0,18,“FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF”` (Clears EPSLOCI)

ilyasahmad · January 22, 2026, 9:16am

Dear Amrraaj,

Thank you for your response.

We have performed all the troubleshooting steps as recommended; however, the SIM is still not getting registered on this specific EC25-E module. The same SIM is registering successfully when used with another EC25-E module at same location.

We have also tried upgrading the firmware version on the affected module to rule out any firmware-related issue:
Old firmware version: EC25EFAR06A06M4G
New firmware version: EC25EFAR06A11M4G

Even after upgrading the firmware, the issue still persists on this particular module.

Kindly find below the AT command outputs for your reference. Based on these outputs, please suggest the next troubleshooting steps or share your observations:

AT+CRSM=214,28643,0,0,18,“FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF”
+CRSM: 144,0,“”

OK
NORMAL POWER DOWN
POWERED DOWN
RDY
+CFUN: 1
ATE1
OK
ATE1
OK
AT+GMM
EC25
OK
AT+CPIN?
+CME ERROR: 14
+CPIN: READY
+QUSIM: 1
AT+CMGF=0
OK
AT+CLIP=1
OK
AT+CREG=2
OK
AT+CGREG=2
OK
AT+GMR
EC25EFAR06A11M4G
OK
AT+COLP=1
OK
AT+CNMI=2,2,0,0,0
OK
+QIND: SMS DONE
AT+CLVL=4
ERROR
AT+QMIC=12000,12000
ERROR
at+qaudcfg=“alc5616/ulgain”,12
ERROR
at+qaudcfg=“alc5616/dlgain”,75
ERROR
AT+QSIDET=0
ERROR
AT+CSCS=“UCS2”
OK
AT+QENG=1,1
ERROR
AT+CSQ
+CSQ: 99,99
OK
AT+CREG?
+CREG: 2,2
OK
+CREG: 3
+CGREG: 3
+CREG: 0
+CGREG: 0

AT+QMBNCFG=“AUTOSEL”
+QMBNCFG: “AutoSel”,1

OK
AT+QMBNCFG=“LIST_ALL”
+QMBNCFG: “List_all”,0,1,1,“ROW_Generic_3GPP”,0x05010824,201806201,“”
+QMBNCFG: “List_all”,1,0,0,“Reliance_OpnMkt”,0x05011B4B,201801051,“405-840”
+QMBNCFG: “List_all”,2,0,0,“TW_Mobile_China_VoLTE”,0x05800301,202005121,“466-92”
+QMBNCFG: “List_all”,3,0,0,“Bouygues_France_VoLTE”,0x05800101,202004151,“208-20”
+QMBNCFG: “List_all”,4,0,0,“Telstra-Commercial_VoLTE”,0x05800716,202002061,“505-01”
+QMBNCFG: “List_all”,5,0,0,“Commercial-Smartfren”,0x05012509,202001041,“510-09”
+QMBNCFG: “List_all”,6,0,0,“VF_Germany_VoLTE”,0x05010444,202005121,“262-02”
+QMBNCFG: “List_all”,7,0,0,“Swis_switzerland_VoLTE_VoWiFi”,0x05010421,201712231,“228-01”
+QMBNCFG: “List_all”,8,0,0,“TF_Spain_VoLTE”,0x05800D43,201909301,“214-07”
+QMBNCFG: “List_all”,9,0,0,“Commercial-DT-VOLTE”,0x05011F27,202006291,“262-01”
+QMBNCFG: “List_all”,10,0,0,“STC_Saudi_VoLTE”,0x0501FE24,202002271,“420-01”
+QMBNCFG: “List_all”,11,0,0,“Reliance_India_VoLTE”,0x05800202,000000000,“405-874”

OK
AT+QCFG=“NWSCANMODE”
+QCFG: “nwscanmode”,3

OK
AT+QCFG=“NWSCANSEQ”
+QCFG: “nwscanseq”,0403010502

OK
AT+QCFG=“BAND”
+QCFG: “band”,0x93,0x1e0000003ff,0x0

OK
AT+QURCCFG=“URCPORT”
+QURCCFG: “urcport”,“uart1”

OK
AT+QENG=“SERVINGCELL”
+QENG: “servingcell”,“LIMSRV”,“LTE”,“TDD”,404,11,71A7B33,429,40940,41,5,5,CE31,-93,-11,-62,16,30

OK
AT+QCFG=“IMS”
+QCFG: “ims”,0,0

OK
AT+QENG=“NEIGHBOURCELL”
+QENG: “neighbourcell intra”,“LTE”,40940,429,-12,-93,-60,-20,30,7,14,8,44
+QENG: “neighbourcell inter”,“LTE”,3601,-,-,-,-,-,-,0,12,5
+QENG: “neighbourcell inter”,“LTE”,1421,-,-,-,-,-,-,0,12,6

OK
AT+CREG?
+CREG: 2,0

OK
AT+CGREG?
+CGREG: 2,0

OK
AT+QNWINFO
+QNWINFO: “TDD LTE”,“40411”,“LTE BAND 8”,40940

OK
AT+QGMR
EC25EFAR06A11M4G_01.001.01.001

OK
AT+QCSQ
+QCSQ: “LTE”,60,-95,119,-11

OK
AT+COPS=?
+COPS: (0,“IND-JIO”,“JIO”,“405872”,7),(0,“404 11”,“404 11”,“40411”,0),(0,“Vi India”,“Vi India”,“40411”,7),(0,“IND airtel”,“airtel”,“40410”,7),(0,“IND airtel”,“airtel”,“40410”,0),(0-4),(0-2)
OK

AmarRaaj · January 28, 2026, 1:43am

Hi ilyasahmad,

From your logs,

AT+QCSQ
+QCSQ: “LTE”,60,-95,119,-11

The last parameter which is the SINR is quite bad, -11dB.
More than 20 dB → Excellent
13–20 dB → Good
0–13 dB → Poor
Less than 0 dB → Very poor

Negative SINR = heavy interference / noisy cell

Is the antenna for you module connected properly?
You can try swapping the antenna if you have another

Also could you run the the same AT commands for the module that is working fine for comparison test and include the AT command below.

AT+CIND

Thank you.

ilyasahmad · January 28, 2026, 10:45am

Hi AmarRaaj,

Kindly find below the AT command outputs of the module that is working fine, along with the relevant logs for comparison. The AT commands used for the comparison test are also included below.

AT+CIND?
+CIND: 0,5,1,0,0,0,1,0
OK

NORMAL POWER DOWN
POWERED DOWN
RDY
+CFUN: 1
ATE1
OK
ATE1
OK
+CPIN: READY
+QUSIM: 1
AT+GMM
EC25
OK
AT+CPIN?
+CPIN: READY
OK
AT+CMGF=0
OK
AT+CLIP=1
OK
AT+CREG=2
OK
AT+CGREG=2
OK
AT+GMR
EC25EFAR06A06M4G
OK
AT+COLP=1
OK
AT+CNMI=2,2,0,0,0
OK
AT+CLVL=4
ERROR
AT+QMIC=12000,12000
ERROR
at+qaudcfg=“alc5616/ulgain”,12
ERROR
at+qaudcfg=“alc5616/dlgain”,75
ERROR
+QIND: SMS DONE
AT+QSIDET=0
ERROR
AT+CSCS=“UCS2”
OK
AT+QENG=1,1
ERROR
AT+CSQ
+CSQ: 99,99
OK
AT+CREG?
+CREG: 2,2
OK
+CREG: 1,“CE31”,“71A7B16”,7
+CGREG: 1,“CE31”,“71A7B16”,7
+QIND: PB DONE
AT+CSQ
+CSQ: 31,99
OK
AT+CPIN?
+CPIN: READY
OK
AT+CIMI
405664620961770
OK
AT+QNWINFO
+QNWINFO: “FDD LTE”,“40411”,“LTE BAND 3”,1421
OK
AT+CGREG?
+CGREG: 2,1,“CE31”,“71A7B16”,7
OK
AT+CSCA?
+CSCA: “002B003900310039003700310039003000300039003900390038”,145
OK
AT+COPS?
+COPS: 0,0,“Vi India VIL”,7
OK
AT+CCWA=1,1
OK
+CREG: 1,“03F6”,“D810”,0
+CGREG: 1,“03F6”,“D810”,0
ATH
OK
+CME ERROR: 100
ATH
OK
+CREG: 1,“CE31”,“71A7B16”,7
+CGREG: 1,“CE31”,“71A7B16”,7
AT+CSQ
+CSQ: 31,99
OK
AT+CIND?
+CIND: 0,5,1,0,0,0,1,0
OK
AT+QCFG=“NWSCANSEQ”
+QCFG: “nwscanseq”,0403010502
OK
AT+QCFG=“NWSCANMODE”
+QCFG: “nwscanmode”,0
OK
AT+QNWINFO
+QNWINFO: “FDD LTE”,“40411”,“LTE BAND 3”,1421
OK
AT+QCSQ?
+QCSQ: 0
OK
AT+QCSQ
+QCSQ: “LTE”,41,-76,100,-13
OK
AT+GMR
EC25EFAR06A06M4G
OK
AT+QCFG=“BAND”
+QCFG: “band”,0x93,0x5,0x0
OK
AT+CSQ
+CSQ: 31,99
OK
AT+QURCCFG=“URCPORT”
+QURCCFG: “urcport”,“uart1”
OK
AT+QENG=“SERVINGCELL”
+QENG: “servingcell”,“NOCONN”,“LTE”,“FDD”,404,11,71A7B16,160,1421,3,3,3,CE31,-74,-13,-43,0,49
OK
AT+QCFG=“IMS”
+QCFG: “ims”,0,1
OK
AT+QENG=“NEIGHBOURCELL”
+QENG: “neighbourcell intra”,“LTE”,1421,160,-12,-72,-43,-20,51,6,12,8,44
OK
AT+CGREG?
+CGREG: 2,1,“CE31”,“71A7B16”,7
OK
AT+CREG?
+CREG: 2,1,“CE31”,“71A7B16”,7
OK
AT+QGMR
EC25EFAR06A06M4G_01.006.01.006
OK
AT+COPS?
+COPS: 0,0,“Vi India VIL”,7
OK
AT+COPS=?
+COPS: (2,“Vi India”,“Vi India”,“40411”,7),(1,“Vodafone IN”,“Vodafone”,“40411”,0),(3,“IND airtel”,“airtel”,“40410”,7),(1,“IN-DOLPHIN”,“DOLPHIN”,“40468”,2),(3,“IND airtel”,“airtel”,“40410”,0),(0-4),(0-2)
OK
AT+EGMR=0,7
+EGMR: “861107035128777”
OK
AT+CSQ
+CSQ: 31,99
OK
AT+CSQ
+CSQ: 31,99
OK
AT+QNWINFO
+QNWINFO: “FDD LTE”,“40411”,“LTE BAND 3”,1421
OK

AmarRaaj · February 9, 2026, 1:57am

Hi Ilyas,

Apologies for the delayed response.

I have sent you an email on this issue. Please check.

EC25-E SIM Registration Failed (GSM/VoLTE)

Kindly find below the AT command outputs of the module that is working fine, along with the relevant logs for comparison. The AT commands used for the comparison test are also included below.

AT+CIND? +CIND: 0,5,1,0,0,0,1,0 OK

AT+CIND?
+CIND: 0,5,1,0,0,0,1,0
OK