Quectel 120R-GL

IoT Modules LTE-A Module
1

Good evening, Quectel Team!
Recently i bought a 4g module as EM120R-GL from second hand oа laptop parts, and it detected onli in pcie on my BPI-R4, but SIM is unreachable.

Input data:

  • Banana PI R4 router under ROOTer OS GoldenOrb_2026-02-26 ( OpenWrt 24.10.3 );
  • Quectel EM120R-GL modem with IMEI 015930000280256 and SN P1C21D528000036;
  • Modem connected to pci-e key-b;
  • lsusb -t show no modem device;
  • lcpci -k show 0003:01:00.0 Unassigned class [ff00]: Quectel Wireless Solutions Co., Ltd. EM120R-GL LTE Modem
    Subsystem: Quectel Wireless Solutions Co., Ltd. Device 2001
    Kernel driver in use: mhi-pci-generic;
  • uname -a
    Linux ROOter 6.6.104 #0 SMP Fri Sep 19 21:19:38 2025 aarch64 GNU/Linux;
  • AT+QGMR
    EM120RGLAPR02A07M4G_18.018.18.018;
  • SIM inserted correctly, in SIM-slot2 on modem;
    -On “Modem status” in web-interface i see:
    Tue Mar 10 16:05:32 2026 : Get Profile 1 Modem 1 is Quectel EM120R-GL
    Tue Mar 10 16:05:32 2026 : Get Profile 1 Warning: IMSI cannot be read - SIM card missing or locked?
    Tue Mar 10 16:05:32 2026 : Get Profile 1 Default Profile Used
    Tue Mar 10 16:05:33 2026 : SimLock 1 No SIM
    Tue Mar 10 16:05:33 2026 : Create MHI Connection 1 SIM Error

Steps to reproduce problem:
AT+QUIMSLOT=1
OK
AT+CPIN?
+CME ERROR: 10
AT+QUIMSLOT=2
OK
AT+CPIN?
+CME ERROR: 14
AT+QCFG=“usbnet”
+QCFG: “usbnet”,0
OK

Questions:

  1. Where i can take latest and previous firmware for this modem?
  2. Whch flashtool can flash modem on OpenWRT router or on Windows OS, and where i can get flashing tool?
  3. What modes does the modem support? (MBIM\QMI\ACM\ECM etc)
  4. How i can change between this modes?
  5. Does this modem support work in USB mode without using an adapter, connected directly in pcie slot with b-key?
  6. If I understand correctly, the -GLAU version can work in USB and PCI mode, but the GLAP version will work onli in PCI mode, right?
  7. Can i flash modem -GLAU instead current -GLAP version?
  8. How do I make the modem see the SIM card?

I am ready to provide any additional information if needed.

2

Dear Customer,

Based on the logs observed, such as +CME ERROR: 10 (SIM not inserted/detected) and +CME ERROR: 14 (SIM busy or interface issue), along with messages like IMSI cannot be read, SimLock No SIM, and MHI Connection SIM Error, this points strongly to a hardware-level issue rather than firmware or software configuration.

In most cases, this happens when the SIM interface is not properly connected or supported by the host setup. Possible causes include incorrect SIM slot mapping (even when switching using AT+QUIMSLOT), SIM signal lines (SIM_CLK, SIM_DATA, SIM_RST, SIM_VDD) not being routed correctly on the adapter or router, or missing SIM power supply (1.8V/3V). It is also quite common for generic PCIe M.2 adapters to not route SIM signals at all, meaning the modem can power up and be detected over PCIe but will never detect a SIM card. Since this is a second-hand module, there is also a possibility of hardware damage on the SIM interface.

To troubleshoot, we recommend first verifying the hardware side. Please confirm that the BPI-R4 SIM slot is properly connected to the M.2 Key-B interface and review the board schematic to ensure SIM routing is implemented. You may also try using a known working SIM card, or test the module using a USB adapter (M.2 to USB), which is often the most reliable way to validate SIM functionality. Additionally, you can run basic AT commands such as AT+CPIN?, AT+QSIMSTAT?, and AT+QCCID to check SIM status. If these commands continue to fail, it would further confirm that the issue is hardware-related.

Questions and Answer:

  1. Where i can take latest and previous firmware for this modem?
    I will send through email. but only for latest firmware

  2. Whch flashtool can flash modem on OpenWRT router or on Windows OS, and where i can get flashing tool?
    QFlash for Windows. No official flashing support via OpenWRT. I will send QFlash tool through email.

  3. What modes does the modem support? (MBIM\QMI\ACM\ECM etc)
    MBIM, QMI and ECM. Usually we will only use between MBIM and ECM. I will send you the driver in email as well

  4. How I can change between this modes?

    AT+QCFG=“usbnet”,X

    Where X:
    0 = QMI
    1 = ECM
    2 = MBIM

  5. Does this modem support work in USB mode without using an adapter, connected directly in pcie slot with b-key?
    No, this modem (GLAP version) cannot work in USB mode when directly connected via PCIe slot

  6. If I understand correctly, the -GLAU version can work in USB and PCI mode, but the GLAP version will work only in PCI mode, right?
    yes, your understanding is correct

  7. Can i flash modem -GLAU instead current -GLAP version?
    You cannot flash from GLAU to GLAP, it will brick the module.

  8. How do I make the modem see the SIM card?
    There are 3 possibilities:
    i. PCIe adapter / BPI-R4 does not route SIM signals
    ii. SIM slot not wired correctly.
    iii. Module damaged