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

DEFINITION: Transmission shift lever will not moved out of the PARK position with the ignition ON and the brake pedal pressed.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

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

Does the shift lever move out of the PARK position?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. Press and release the brake pedal several times while observing the TCC Brake Switch parameter in the powertrain control module (PCM) data list.

Does the parameter turn ON and OFF with the brake pedal movement?

Go to Step 4

Go to Diagnostic Starting Point - Lighting Systems

4

  1. Turn OFF the ignition.
  2. Disconnect the automatic transmission shift lock control solenoid at the connect of the automatic transmission shift lock control solenoid.
  3. Turn ON the ignition, with the engine OFF.
  4. Press and hold the brake pedal.
  5. Attempt to move the shift lever out of the PARK position.

Does the shift lever move out of the PARK position?

Go to Step 5

Go to Step 6

5

Test the control circuit of the automatic transmission shift lock control solenoid for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 7

6

Inspect for poor connections as the harness connector of the automatic transmission shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Inspect for poor connections as the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the automatic transmission shift lock control solenoid. Refer to Automatic Transmission Shift Lock Control Actuator Replacement .

Did you complete the replacement?

Go to Step 10

--

9

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 3