GM Service Manual Online
For 1990-2009 cars only

Shift Lever Can Be Moved without Brake Pedal Depressed Buick

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: Shift Lock Control Connector End Views

DEFINITION: Transmission shift lever does not lock in the PARK position with the ignition ON and the brake pedal not pressed.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Apply the parking brake and block the wheels.
  2. Turn ON the ignition, with the engine OFF.
  3. 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

  1. Turn OFF the ignition.
  2. Connect a test lamp between the ignition 1 circuit at the automatic transmission shift lock control switch and a good ground.
  3. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 4

Go to Step 11

4

  1. Turn OFF the ignition.
  2. Connect a test lamp between the automatic transmission shift lock control switch signal circuit at the automatic transmission shift lock control switch and a good ground.
  3. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 5

Go to Step 9

5

  1. Turn OFF the ignition.
  2. Connect a test lamp between the automatic transmission shift lock control switch signal circuit at the automatic transmission shift lock control solenoid connector and a good ground.
  3. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 6

Go to Step 12

6

  1. Turn OFF the ignition.
  2. Disconnect the electrical connector of the automatic transmission shift lock control solenoid.
  3. Connect a test lamp between the automatic transmission shift lock control solenoid signal circuit and the automatic transmission shift lock control solenoid controlled ground circuit at the connector of the automatic transmission shift lock control solenoid.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 10

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Connect a test lamp between battery positive voltage (B+) and the automatic transmission shift lock control solenoid controlled ground circuit at the connector of the body control module (BCM).
  3. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 13

Go to Step 8

8

Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 16

9

  1. Inspect for proper adjustment of automatic transmission shift lock control switch. Refer to Stop Lamp Switch Adjustment .
  2. Inspect for poor connections at the automatic transmission shift lock control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 14

10

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

Did you find and correct the condition?

Go to Step 17

Go to Step 15

11

Repair the open in the ignition 1 power feed circuit. Refer to Circuit Testing and to Wiring Repairs .

Did you complete the repair?

Go to Step 17

--

12

Repair the open in the automatic transmission shift lock control switch signal circuit. Refer to Circuit Testing and to Wiring Repairs .

Did you complete the repair?

Go to Step 17

--

13

Repair the open in the automatic transmission shift lock control solenoid controlled ground circuit. Refer to Circuit Testing and to Wiring Repairs .

Did you complete the repair?

Go to Step 17

--

14

Replace the automatic transmission shift lock control switch. Refer to Stop Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 17

--

15

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 17

--

16

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

Did you complete the replacement?

Go to Step 17

--

17

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2