GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn the ignition switch to RUN.
  2. Do not press the brake pedal.
  3. Attempt to move the gear selector lever out of the PARK position.

The shift interlock feature prevents the gear selector lever from shifting out of PARK.

Automatic Transmission Shift Lock Control Inoperative

2

  1. Turn the ignition switch to RUN.
  2. Press the brake pedal.
  3. Attempt to move the gear shift lever out of the PARK position.

The gear selector lever shifts out of the PARK position.

Automatic Transmission Shift Lock Control Always On With Ignition in RUN

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.