GM Service Manual Online
For 1990-2009 cars only

Vehicle with an automatic transmission have a shift-lock control system. You have to fully apply the brake pedal before you can shift from P (Park) when the ignition is in the ON/RUN position. See Automatic Transmission Operation.

If you cannot shift out of P (Park) while holding the brake pedal down, try this:

  1. Set the parking brake.
  2. Turn the ignition off and remove the key.
  3. Remove the cover over the shift-lock release slot by prying it off using a small, flat object. The shift-lock release slot is located at the top of the shift lever.

  4. Object Number: 1757442  Size: B3
  5. Insert the key into the shift-lock release slot and press and hold the key.
  6. Shift to N (Neutral).
  7. Remove the key from the shift-lock release slot, insert the key into the ignition and start the engine.
  8. Replace the shift-lock release slot cover.
  9. Apply and hold the brake pedal fully and release the parking brake.
  10. Shift to the gear you want.
  11. Have the system fixed as soon as you can.