I was trying this engineering mode for my EM7355 and it worked. My aim is to write the SAR BACKOFF settings permanently into the modem. Unfortunately even when I did the settings in eng. mode they were reverted to initial condition after changing the SIM and having the FW autoswitched to the carrier specific version.
Can you please help me how to do it steadily?
I also tried to apply the SARBACKOFF settings via the configuration.ini file, but that way they were not even set just once.
B4316 driver pack and windows 10 is used. Generic FW is 05.05.58.00. In the driver pack there is Verizon, ATT, Rogers, Sprint, Bell, Telus defined with their FW/nvu.
Several years later this undocumented anti-feature is now fixed:
AT!OPENLOCK? 81F2B4F0A9E06DF2 OK AT!OPENLOCK="21A68A014A39E0E8" OK AT!PCFCCAUTH=0 OK AT!PCFCCAUTH? NV Setting: 0 FCC Auth Enabled: 1 FCC Lock State: 1 OK AT!PCFCCAUTH=0 OK AT!RESET OK at!entercnd="A710" OK AT!PCFCCAUTH? NV Setting: 0 FCC Auth Enabled: 0 FCC Lock State: 0
Why not? qmicli can run the very same command on the cdc-wdm port while in MBIM mode, it will run “QMI over MBIM” transparently.
Could you please tell me if that FCC locked device had the generic Sierra USB vid:pid (1199:9079) or a different laptop-vendor-branded one? E.g. HP, Dell?
That was some years ago, OpenWrt had no umbim with QMI support (or uqmi was not able to send FCC, something of the two). FCC in umbim/uqmi was available some time later, so while still annoying, it worked. The original post was not in the OpenWrt environment obviously. Don’t know if ModemManager would have worked back then, haven’t tried it mainly because the device I was using had little flash memory - I think.
Not sure, it’s 1199:9079 now. It was in use on a OpenWrt device for some years (not any longer) and since I had it around without any use I inserted it into a Thinkpad T460 (Win 8.1). Although automatic driver installation went fine the device was still in LPM.
I got the device as a gift, my guess is that it was originally for a Thinkpad.
I believe 9079 is a Lenovo specific PID with FCCAUTH enabled by default. The generic MC7455/EM7455 PID is 9071.
Heads up for anyone with this FCC locked modems also using ModemManager: FCC unlock procedure | ModemManager