Cannot get a connection on the T-mobile network


I received the SODAQ-SARA-R410M, registrated my SIM on the t-mobile portal and placed the SIM into the board. After uploading the Passthrough Sketch

So far so good, however, I cannot get connection with T-mobile : (no value of one after AT+CGATT?).

+URAT: 8

+CGDCONT: 1,“IP”,“”,“”,0,0,0,0

+CFUN: 1

+COPS: 0


+CSQ: 99,99

+CEREG: 2,0


+CME ERROR: No connection to phone

Does anybody have a suggestion for me to resolve the issue?
Thanks in advance!


Seems like you’re not registered to the network yet. +CEREG:2,0 means that it’s trying to connect, but isn’t connected yet. You’re looking for CEREG:1,1 or CEREG:1,5 (for roaming). Try and use AT+CEREG=1 at the start of the. This enables URC’s that notify you on the CEREG status. Once it is connected it will notify you via a URC. This will usually take about 20-40 seconds.Waiting at the right moments makes the difference.

Good luck!


Thanks Michael,

I would be happy to try this, but: modem is not responsive anymore. I got an issue comparable with the one descirbed in this topic: AT command passthrough stopped working meaning that other sketches (without using the modem) work fine. If I type AT however, I get no response anymore.

Tried this sketch: and this was the result:
17:23:02.787 -> Initializing and connecting…
17:23:10.602 -> Failed to connect to the modem!

Removing the (T-mobile) SIM card makes it able to respond to AT commands until I do something like:
17:36:45.791 -> AT+CGDCONT=1,“IP”,“”
17:36:45.791 -> +CME ERROR: SIM PIN required
17:37:00.111 -> AT+CPIN=“0000”
17:37:00.111 -> +CME ERROR: SIM not inserted

of course…

Hi @rienk,

The COPS command should return “OK” when you are connected to the network.
This can take up a few minutes. [quote=“rienk, post:1, topic:2164”]
+CSQ: 99,99

AT+CSQ is returning the signal quality.
99 means no signal, you can repeat sending this command to check if you have a signal or if the signal gets better.
A CSQ of 8 or higher (not 99) should be ok for sending a message.

After a successful connect you can send the command AT+CFUN=15 to save the connection settings into the module. And make the next connect much faster.

Did you uncomment the // #define R4XX ?

Best regards,