You gotta make sure that your wifi password is the absolute correct password. you can look up your error codes here: http://en-americas-support.nintendo.com/app/answers/landing/p/606/c/260 but the 51330 on the wii does indicate that there is an issue with your wifi password. one of the best ways to check your wifi password is actually on your computer under your internet settings> properties> security.
Then check the box to show your password and match it up on your wii. if changing the settings in the actual connection doesnt work try making a new connection entirely. lastly if these steps dont work do some troubleshootong on your actual router and give it a reset (unplug it for a few seconds and plug it back in). hopefully all this helps if not let me know on here or you can always call the Nintedo Tech Support number: 1 (800) 255-3700
again, hope this helps