Why is my pressure cooker not building pressure?

The pressure cooker may not be building pressure due to several reasons: the lid may not be sealed properly, the steam release valve may be misaligned, there may be insufficient liquid in the pot, the sealing ring may be damaged or improperly placed, the exhaust valve may be clogged, or the pressure sensor may be faulty. Check each of these components and ensure the lid is securely locked in place with adequate liquid to generate steam.