GM Service Manual Online
For 1990-2009 cars only

Important: Review the system in order to familiarize yourself with the system functions.

Refer to Automatic Transmission Shift Lock Control Circuit Description .

Step

Action

Normal Result(s)

Abnormal Result(s)

1

  1. Turn ON the ignition, with the engine OFF.
  2. Depress the brake pedal.
  3. Attempt to move the shift lever out of the PARK position.

The transmission shift lever will move out of the PARK position.

Automatic Transmission Shift Lock Control Always On with Ignition in Run

2

  1. Shift to the PARK position.
  2. Release the brake pedal.
  3. Block the wheels.
  4. Attempt to move the shift lever out of the PARK position.

The transmission shift lever will not shift out of the PARK position.

Automatic Transmission Shift Lock Control Inoperative

Refer to the appropriate symptom diagnostic table for further diagnosis.