GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: Shift Lock Control Connector End Views or Automatic Transmission Related Connector End Views

DEFINITION: Transmission shift lever does not lock in the PARK position with the ignition OFF.

1

Did you perform the Symptoms - Automatic Transmission Shift Lock Control tests and perform all the necessary inspections?

Go to Step 2

Go to Symptoms - Automatic Transmission Shift Lock Control

2

  1. Move the shift lever to the PARK position.
  2. Turn OFF the ignition.
  3. Press and hold the brake pedal.
  4. Attempt to move the shift lever out of the PARK position.

Does the shift lever move out of the park position?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Connect a test lamp between the park lock solenoid ignition 1 voltage circuit and a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

Inspect for poor connections at the harness connector of the park lock solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5

Repair the short to battery positive voltage in the park lock solenoid ignition 1 voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 7

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6

Important: Depress the button on the side of the shift lock actuator. With the button is depressed, cycle the plastic straw within the shift lever 3 to 5 times. The straw should move smoothly and freely except near the top of the travel where additional force will be required to mechanically actuate the park lock mechanism inside of the shift lock actuator. If there is stick/slip or abnormal friction while cycling the plastic straw or if the straw is altogether stuck in the lever, the entire control assembly (shifter and shift lock actuator) needs to be replaced. Refer to Transmission Control Replacement . If there is no abnormal friction, replace the shift lock actuator. Refer to Automatic Transmission Shift Lock Control Actuator Replacement .

Did you complete the repair?

Go to Step 7

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7

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2