I have a 2006 Buick Rainier that will not go out of park. It starts up just fine, but will not shift. What is wrong with it?

. Test all under dash and under hood fuses with a test light or multimeter.

. Ensure the brake lights come on, when the pedal is depressed; otherwise the brake pedal switch (or Brake Pedal Position Sensor) may need adjusting/replacing.