GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

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

Shift interlock feature prevents gear shift lever from shifting out of PARK position.

Automatic Transmission Shift Lock Control Inoperative

2

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

Gear shift lever shifts out of 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.