Comment 18 for bug 1198283

I have the same problem on 16.04. The usb mode switch does not trigger properly.

The following workaround works for me:

To fix automatic switching, a new udev rule is required (do not modify the original automatic rule in /lib/udev/rules.d/40-usb_modeswitch.rules). Create the file /etc/udev/rules.d/39-usbmodeswitch-custom.rules with:
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# Hack: specifc rule for switching Huawei E3276 and similar modems
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="12d1", ATTRS{idProduct}=="1f01", RUN+="/etc/udev/rules.d/switch_usb_mode.sh"
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Next create an executable script (chmod +x) /etc/udev/rules.d/switch_usb_mode.sh:
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#!/bin/bash
# switch HUAWEI modem to modem-mode using Huawei new mode option J
usb_modeswitch -J -v 0x12d1 -p 0x1f01
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