Connectivity Issue with Teltonika FMC920 Devices


I’m reaching out because I’m encountering a recurring issue with my Teltonika FMC920 devices and I’m wondering if anyone here has experienced something similar or has any suggestions for a resolution.

I’ve recently purchased my first FMC920 units, but I’m facing a significant problem: they keep disconnecting from the network every 1 minute and 10 seconds. This has been happening consistently since last week, rendering the devices almost unusable for me in their current state.

I’ve tried some basic troubleshooting like restarting the devices and checking network settings, but the issue remains unresolved. I haven’t been able to pinpoint a specific cause for these frequent disconnections.

I am including some logs from the devices to provide more detail. If anyone has experience with these devices or has faced similar issues, I would greatly appreciate any insights or suggestions for a fix.

[2024.01.22 15:49:22]-[ATCMD]	>>[224] +CGEV: NW PDN DEACT 1
[2024.01.22 15:49:22]-[AT.RSP]	CGEV Response: Network PDN conn. deactivated
[2024.01.22 15:49:22]-[ATCMD]	>>[224] +QIURC: "pdpdeact",1
[2024.01.22 15:49:22]-[ATCMD]	>>[224] +QJDR: JAMMED
[2024.01.22 15:49:22]-[MODEM.ST]	AT dead RSNs: 133, 0, 0, 0, 0, 0, 0, 0, 0, 0
[2024.01.22 15:49:22]-[MODEM.ACTION]	GSM Update Reason:Eventual
[2024.01.22 15:49:22]-[ATCMD]	<<AT+CPAS

[2024.01.22 15:49:22]-[NETWORK]	[IND] unexpected deactivation of pdp detected!
[2024.01.22 15:49:22]-[NETWORK]	pdp deactivation detected! account id: 52, cbm result: 0 / ok, error cause: 0
[2024.01.22 15:49:22]-[NETWORK]	Flags Cleared, Caller:[989]
[2024.01.22 15:49:22]-[TLS]	M2M_NET_TLS_Deinit:0
[2024.01.22 15:49:22]-[ATCMD]	>>[133] +CPAS: 0
[2024.01.22 15:49:22]-[ATCMD]	>>[133] OK
[2024.01.22 15:49:22]-[ATCMD]	<<AT+QICLOSE=0

[2024.01.22 15:49:22]-[ATCMD]	>>[193] OK
[2024.01.22 15:49:22]-[ATCMD]	<<AT+CIMI

[2024.01.22 15:49:22]-[REC.SEND.1]	Caller: 1330, queueing recsend1 task job type: 2/close link
[2024.01.22 15:49:22]-[NETWORK]	VR socket 0 closed! Real:0
[2024.01.22 15:49:22]-[NETWORK]	[SOCKET.CLOSE.0991] Waiting for close result, waiting: 10 sec

Thanks in advance for any help!


Good day, based on the log it suggests an intentional or unintentional deactivation of the cellular network connection, potentially caused by jamming.

Other possible reasons:

  1. The device might have reached its data limit or exceeded its allowed usage.
  2. There could be a temporary network outage or issue in the service area.
  3. The SIM card might be malfunctioning.

Note: Please contact your network provider and the Teltonika local support from your region to investigate this issue.

Please create an HD ticket or contact your sales manager. If you don’t have any contact with our Sales managers, please contact with them on our official website and click on the “Contact Us” button. When you will click, please fill the form and submit it. Note: as a topic, please choose “Vehicle telematics”. Or you can send an e-mail with description of your situation to us: Teltonika - IoT, Internet of Things When contacting Us, please provide: IMEI/Logs/Configuration file/Intenational GSM number/Firmware version/ect , please follow these recommendations: Recommendations for filling a query description - Wiki Knowledge Base | Teltonika GPS

Best Regards
Maynard C


First of all, thank you for your response Maynard_Castro.

I wanted to share an update on the issue. I am pleased to inform that I have managed to resolve the problem, and I think the solution might be useful for others as well.

Initially, I was not aware that I needed to add a Roaming Operator List to these devices. This was a new requirement for me, as my other 4G devices from different brands did not need this configuration. After thoroughly reviewing the logs from the FMC920 units, I noticed several errors related to Roaming and GPRS. This clue led me to investigate further.

The solution was to update the settings by including a list of MCC (Mobile Country Code) and MNC (Mobile Network Code) specific to Brazil, which I found on the website Once I made this adjustment, the devices began to function without the frequent disconnections I was experiencing.

I wanted to share this resolution with the community, especially for those who might be new to Teltonika devices or transitioning from other brands. It seems that these specific settings are critical for ensuring stable connectivity.

Hope this helps someone out there!

Best regards,

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