Things You'll Need
Instructions
First, enter the following Action Replay DSi code:
02064ec8 47104a00
02064ecc 02000031
94000130 fcfe0200
02066db8 47084900
02066dbc 02000001
02066b88 47084900
02066b8c 02000051
12066b7c 000046c0
d2000000 00000000
94000130 fcfe0100
02066db8 95019000
02066dbc 90022000
02066b88 43200400
02066b8c 1c28900d
12066b7c 0000d107
d2000000 00000000
62000000 95019000
e2000000 00000080
95019000 90022000
1c28b40d f0684907
1c01fd4d 2901bc0d
4902d101 49024708
00004708 02066dc1
02066d9f 00000000
95019000 69384a04
98046010 4b019a09
00004718 02064ed1
0200002c 00000000
43200400 4907b401
f0686809 1c01fd27
2901bc01 4904d001
900d4708 49031c28
00004708 0200002c
02066b7f 02066b91
d2000000 00000000
The only way to get Suicune in Pokemon Pearl is to transfer one from Pokemon FireRed/LeafGreen. Start up your version of the game that has Suicune and put it in one of the boxes in your in-game PC. After you have done so, turn off your DS.
Make sure you have both FireRed/LeafGreen and Pearl inserted into your DS and turn on the console. When you are at the menu screen of Pokemon Pearl, you will be given an option to transfer Pokemon from one game to another. Select this option and choose Suicune as the Pokemon you want to transfer.
Start up Pokemon Pearl and head to the Pal Park. The Pal Park is the place where you can place Pokemon from FireRed/LeafGreen in order to catch them. To get to the Pal Park, start in Sandgem Town and surf south along the waterway. Follow that route to the end and you will find an island. At the back of that island is the Pal Park.
Go in the building at the Pal Park. When you go in, you will be given six Pokeballs, which you use to capture the Pokemon you transfer over. Head into the wild grass and wander around until the fight with Suicune starts up. Capture Suicune and make him the first Pokemon in your party.
Turn off the DS and load up Action Replay. If you entered the code in Step 1, proceed back to your game file. Select your "Trainer Card" and press the "A" button and right trigger at the same time. Doing so will activate the code and make every Pokemon in your party shiny. You now have a shiny Suicune.