Intel PRO/Wireless 3945ABG Mini-PCI Express Adapter

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Revision as of 16:24, 7 November 2009 by Yak (Talk | contribs) (Hardware switch)

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This is a Mini-PCI Express WiFi Adapter


  • Chipset: Intel WM3945AG
  • IEEE Standards: 802.11a, 802.11b, 802.11g
  • PCI ID: 8086:4227

Mini-PCI WiFi Adapter

IBM Partnumbers

  • 41A4068
Only the IBM Parts will work, any other parts will give an 1802 error on Post because the sub-vendor PCI ID is different, see Problem with unauthorized MiniPCI network card for more details

Also known (in IBM literature) as....


  • Linux has the ipw3945 and the iwl3945 drivers. iwl3945 should be used as it is newer and actively developed. Also, Kernel 2.6.24 drops the old wireless-stack so ipw3945 won't compile.
  • If you are not in the US, more Wifi channels are available (EU: 13 instead of 11). If you cannot see your Wifi, but you know it is there, check if it is on Channel 12 or 13.
    • To fix, create /etc/modprobe.d/iwl3945-fix and add the following line: "options cfg80211 ieee80211_regdom=EU". Reload to the driver for the change to become active: "modprobe -r iwl3945", then "modprobe iwl3945".

Hardware switch

Operating a radio transmitter is not permitted in aircraft, and there are times where security requires that your wireless connection be shut down. Some ThinkPads have a hardware switch that disables the wireless network. Here it is on the on position:

(ThinkPad R60 radio switch in the ON position)

Note: the switch is somewhat hard to locate depending on the ThinkPad model; look for it at the front or left front edge of the device.

To be certain that your wireless connection is not transmitting, turn the switch off. Just remember to turn it back on when you once again need wireless access. If the switch is off, you might encounter following Log-Message on Startup:

 ipw3945: Radio Frequency Kill Switch is On:
 Kill switch must be turned off for wireless networking to work.

Also, when you try to activate (iwconfig) your wireless connection with the switch off you may see the error,

 Error for wireless request "Set Mode" (8B06)

The number 8B06 does not matter. It merely represents the wireless mode (auto, ad-hoc, managed, master), none of which will work with the wireless switch off.

ThinkPads this card may be found in