My wii is not signing on line error code 51331 is a it says please help

Hello xklown777
This error code usually indicates a problem relating to wireless security. Please try the following troubleshooting:

1. Are you using WEP or WPA security on your router?

Log into the router using the default IP (if you don´t know this, consult your router's manual for assistance). Locate the "wireless security" section of your router settings and find the WEP or WPA key.
If you are using 64-bit encryption, the WEP Key must be a 10-character key consisting of numbers or letters A through F.
If you are using 128-bit encryption, the WEP Key must be a 26-character key consisting of numbers or letters A through F.
The WEP Key must be a Hexadecimal (0-9, A-F, no other special characters or letters).
If your router has multiple slots for a WEP Key, make sure the active key is the one in the #1 slot.
If you are using WPA, the Wii console is compatible with the following types:
WPA - PSK (TKIP)
WPA - PSK (AES)
WPA2 - PSK (AES)

2. If your WEP or WPA key is correct, then the problem might be related to MAC address filtering:

From the router settings, locate the "MAC address filter" settings (also known as "access control", "access list", or "network filter" depending on your router model).
If the Mac address filter is set to "enabled", then you must add the Wii's MAC address to the "allowed" list. You can locate the Wii's MAC address from the "console information" page (located under "Internet" in the Wii Settings). If the Mac address filter was disabled, then continue troubleshooting.

3. Power cycle your router and modem by unplugging them both from the wall. Wait a few minutes, and plug the modem back in. Wait a couple of minutes for the modem to initialize, then turn on the router. Try to connect the Wii console online and test for proper response.

The above steps usually resolve the problem. If the error message still comes up, there are other ways I can help you, but it would help if you could tell me the model number of your router, as some models have compatability problems with the Wii.

Hope this helps.

ajblaj