What kind of router do you have?
I did a quick Google search for the error code you're getting, and found the following instructions on a Gizmondo forum. Edited for spelling, grammar & clarity.
[tt]1. Firstly go to your routers setup screen (which is typed in as your web address in the internet browser. They are normally something like 192.168.1.?, all are different.)
2. Next go to the initial settings page on your router and look for DHCP Client List or similar, there you will see your DS's given IP Address.
3. Then pick up your DS and go to your Nintendo WFC Settings, then Nintendo Wifi connection settings.
4. Click Connection 1, then Search for an Access Point. Click on the found connection if one is found.
5. Next enter WEP key if any (found in your router security settings).
6. On Auto Obtain IP Address click no, then edit the IP address to be the same address given on the router webpage (in step 2).
7. Next enter Subnet Mask as 255.255.255.0
8. Enter Gateway(edit) as the same number you used to get into your router via the webpage in step 1, e.g. 192.168.?.?
9. Click no on Auto Obtain DNS. Click (edit) on Primary DNS and use same number as router again. Next click (edit) on Secondary DNS and use the same number yet again![/tt] (I remember doing this, it is tedious as hell).
[tt]10. Click Save Settings and then Test Connection. If all is well, it should work.
If no access point was found in step 4, click Manual Set Up and follow the above... Good luck![/tt]
So yes, try that in order, and let us know if it worked or not.