There's no single "max all motives" cheat in The Sims 1 on PS2, but the existing codes and legitimate strategies achieve the same result.
Note: PS2 version lacks boolprop testingcheatsenabled true (PC's debug cheat). No shift-click object manipulation.
Use motherlode once to skip the early grind. Use move_objects on for building freedom. But don't cheat motives—balancing needs is the core gameplay loop of The Sims. The challenge of juggling 8 Sims' bladders before work is where the stories happen.