I am following up on a previous thread, as the issue I had reported is still present and unresolved.
I am using a RUTX50 router (SN: ****, Hardware Revision: 0202), currently operating with firmware version RUTX_R_00.07.13.4.
Starting from firmware versions released after that (including RUTX_R_00.07.14.1 and later), the router exhibits a recurring issue: every 8 – 12 minutes, SIM 1 is disconnected, the corresponding SIM LED turns off, while the 4G/5G and signal strength LEDs remain on. The issue affects all firmware releases tested since May 2025 (including RUTX_R_00.07.15.2) and is independent of the SIM card or slot used. The SIM card itself functions properly on other devices.
Upon analyzing the logs (gsm.log, system.log), I found the following:
ESM errors ("esm_error": 33);
Modem initialization errors (Unable to retrieve modem usb info, I/O error);
No Mobile data: Disconnected events in log.db;
No watchdog or failover services enabled (all advanced services are disabled).
The internal modem is a Quectel RG501Q-EU, currently running the following firmware:
RG501QEUAAR12A11M4G_04.200.04.200
Based on the above findings, I strongly suspect an incompatibility between the newer Teltonika system firmware versions and this modem firmware, likely due to changes in power management, SIM slot selection logic, or 5G NSA handling.
I kindly ask if you could provide:
an updated .bin firmware file for the Quectel RG501Q-EU modem, preferably version A13 or newer;
and any official Teltonika instructions for applying the update manually via SSH.
I remain available to share additional logs or technical details if needed.
Thanks for providing so many details about your issue & also sharing the things you’ve already tested.
The "esm_error": 33 you’ve mentioned, indicates that there could be an issue with the APN that you are currently using. In other words, it may not be set to what it needs to be, or you’re using the incorrect one. I recommend navigating to Network → WAN → Mobile Interface → Edit in the WebUI and manually setting the APN by disabling “Auto-APN”. Then, check if the issue persists.
You can find more information about ESM/EMM reject causes on this website: LTE Release Causes.
If the suggestion doesn’t help you out, kindly reply back and we’ll continue troubleshooting.
thank you for your reply.
I’ve already done that — I manually set the APN after confirming the correct value with my mobile provider, but the issue still persists.
A few things I’d like to mention - first, we’ll have to move to a different communication channel so I can collect the troubleshoot file from your device to further analyse this issue. The file may contain passwords, public IP addresses, serial numbers, and such. To avoid leaking this information, we have sent you a form to fill out, which you will receive in your e-mail inbox that you have registered your account with in the forums. In the Ticket ID field of the form, please enter the ID of this thread, which is 15956.
Secondly, just to confirm - are you using the default power supply with our device, or are you using some other power source to power it?
I’ve completed the form as requested.
Yes, I’m using the default power supply that came with the device.
Also, I’d like to mention that there’s another topic “Intermittent SIM Recognition Issue After Firmware Update RUTX_R_00.07.14.2 (2025.05.09)“ open regarding the same issue, where other users have confirmed that the problem seems to be related to the internal modem version.
I’ve already reached out to you through the e-mail you’ve provided in the form, however, I have not received any response. If you have sent one, please ensure that you’re pressing “Reply” on the e-mail I’ve sent to you and please try sending your reply again.
