Just to be clear, I was able to update the firmware over UART0, once I used the correct file.
We do have a different issue related to HL7812 USB failure - IoT Modules - Sierra Wireless Forum
Is there a command I can send via UART0 to make the modem go to the factory default settings.
We switched the modem from UART1 to USB but the USB is not working and we are now stuck.
I am hoping there is a way to reset the modem to factory default (using the bootloader).