Here are all the cheats I know for the sims 2.
Some cheats may have to be activated whilst the game is paused.
When cheats are activated they will either activate automatically or you will have to go to the gnome with your sim and activate them from there.
You need to activate the gnome code first to enable the cheats to be activated.
Set skill level: Triangle,Circle,Square,R2,Left
Fill all motives: Up,Circle,Up,Left,L2
9,999 Simoleons: R1,L1,R2,Right,Left
Clock 6+ hours(Warning! If your sim is at work it may affect him coming back on time!): Circle,Square,L1,Up,Down
Unlock all locations: Circle,L2,Left,Circle,Up,Circle
Team Photo: Right,Down,Right,Down,Right
Unlock all clothes: Square,R2,Down,Right,Square
Unlock all objects: L2,Circle,Down,Left,Right
Unlock all recipes: R2,Square,Up,Down,Right,X
Horn Audio: R1,L1,R1,L1,Triangle
Hope I Helped
Happy Gaming ;-)