The following are known Action Replay Codes for SimCity DS on Nintendo DS (NDS).

Game ID: AC3E-64E5C6F3

Press L+R For Landmarks
94000130 fcff0000
d5000000 00000001
c0000000 00000037
d6000000 0224299c
d2000000 00000000

MONEY CODES:

Press L+UP for Max Funds
94000130 fdbf0000
020c7d2c 3b9ac9ff
d0000000 00000000

Press L+DOWN for No Funds
94000130 fd7f0000
020c7d2c 00000000
d0000000 00000000

POPULATION CODES:

Press R+UP for Max Population
94000130 febf0000
021f699c 3b9ac9ff
d0000000 00000000

Press R+DOWN for No Population
94000130 fe7f0000
021f699c 00000000
d0000000 00000000