While playing the game, press Down, X, Right, Left, Right, R1, Right, Down, Up, Triangle. You still must be quick in order to save Madd Dogg. Note: If you encounter this problem, enable the 'Slow motion' or 'Adrenaline effects' codes to get there faster. When this number has been exceeded, Madd Dogg will jump off the roof in a few seconds, making it impossible to save him. The game will prevent you from completing this mission if codes have been used excessively this number appears to be cheats being used 500 or more times.
You should be careful on using cheat codes too frequently until you complete the mission where you save Madd Dogg from jumping off the casino rooftop. Strategy Guide/Walkthrough/FAQ 100% Completion Guide Car Locations Guide Girlfriend Guide Horseshoes Location Guide Property Guide Tag Locations Guide Map: Vehicles Map: Weapons Map: Properties Map: Tags, Oysters, Horseshoes, Photos