OK, what code did you use exactly? Are we talking *#*#4636#*#* or *#*#INFO#*#* or something else?
If it was one of those above that you used, and then the Ping Test, they you probably are needing to manually I re-input the SMSC number and press update.
Since I don't know your carrier, I can't tell you for sure what your numbers should be. However a quick search, or contacting your carrier, should be able to get you the number.