I have Windows 8 tablet (Windows 8.1 Bing x64) with internal WWAN modem Sierra Wireless EM7345. It is composite device, LTE modem and GPS.

When the mobile connection is established, tablet goes to connected standby mode and then wakes-up lately, the modem device sometimes disappears from Device Manager and there is an unknown device with question mark icon instead. It has different VID/PID that's why Windows can not find drivers for it. When I Uninstall this phantom device from Device Manager and perform 'Scan for hardware changes' the WWAN device is back (now with correct VID/PID) and works.

The issue is reported by multiple customers. Firmware and BIOS update does not help. I have tried to diagnose the issue by USB3HWVerifierAnalyzer, below is the summary:

Record #1 (Key = 0x1fffc6261fd8)
  VendorID/ProductID: 0x1199/0xa001  <--- correct VID/PID
  DeviceInterfacePath: \??\USB#VID_1199&PID_A001#xxxx#{a5dcbf10-6530-11d2-901f-00c04fb951ed}
  DeviceDescription: USB Composite Device
  PortPath:  0x3, 0x0, 0x0, 0x0, 0x0, 0x0
  All errors encountered:
    #1: (UsbHub3/132): Device Control Transfer Error
    #2: (UsbHub3/132): Device Control Transfer Error
    #3: (UsbHub3/132): Device Control Transfer Error
    #4: (UsbHub3/132): Device Control Transfer Error
    #5: (UsbHub3/132): Device Control Transfer Error

Record #2 (Key = 0x1fffc63d8e28)
  VendorID/ProductID: 0x1519/0xf000  <--- the unknown device VID/PID
  PortPath:  0x3, 0x0, 0x0, 0x0, 0x0, 0x0
  All errors encountered:
    #1: (UsbHub3/160): Request for Device Descriptor Failed
    #2: (UsbHub3/132): Device Control Transfer Error
    #3: (UsbHub3/75): Validation Failure of Device Descriptor
    #4: (UsbHub3/176): DescriptorValidationErrorBulkEndpointInvalidWMaxPacketSiz

Record #3 (Key = 0x1fffc6802298)
  DeviceInterfacePath: \??\USB#ROOT_HUB30#4xxx#{f18a0e88-c30c-11d0-8815-00a0c906bed8}
  PortPath:  0x82, 0x0, 0x194b, 0x3
  All errors encountered:
    #1: (UsbHub3/179): Client Initiated Recovery Action
    #2: (UsbHub3/179): Client Initiated Recovery Action

Do you have an idea what can cause the issue ? It seems to be related to power management but there is no setting for wireless devices in advanced power profile. It is MBIM device so it uses Microsoft generic drivers. The only proprietary device driver is the GPS but the issue occurs with GPS turned off as well.

I don't think the vendor will be much of help except "Reinstall windows, reinstall driver, replace the WWAN modem". That's why I am trying to diagnose it myself. It is not the first time that their WWAN device driver was buggy, after all. I have also ETL file for the session.

Thanks.

Hello Petr Vones,

If my understanding is right, you have an internal WWAN modem Sierra Wireless EM7345 and it sometime disappears in the device manager and need to scan for hardware change.

Have you made any changes before this issue?

As this issue is related to Sierra Wireless EM7345, to receive better support, it is recommended to contact the manufacturer.

Best regards,
Fangzhou CHEN

Hello,

did you got any solution for this issue ?

Thanks

Hello,

did you got any solution for this issue ?

Thanks

Partially. It is firmware issue. There is new EM7345 firmware FIH7160_V1.2_WW_01.1415.07 that solves some issues but it is still not 100% reliable.

• Marked as answer by Petr Vones 1 hour 18 minutes ago

Hello,

did you got any solution for this issue ?

Thanks

Partially. It is firmware issue. There is new EM7345 firmware FIH7160_V1.2_WW_01.1415.07 that solves some issues but it is still not 100% reliable.

• Marked as answer by Petr Vones Sunday, February 08, 2015 10:27 AM