2004 Buick will not shift out of park?

If your 2004 Buick won't shift out of park, it may be due to a faulty brake shift interlock system, which prevents shifting unless the brake pedal is pressed. Check if the brake lights are functioning; if not, it could indicate a blown fuse or a bad brake light switch. Additionally, ensure the gear shift mechanism is not obstructed and that the Transmission Fluid is at the proper level. If the issue persists, consulting a mechanic for a thorough diagnosis may be necessary.