GM Service Manual Online
For 1990-2009 cars only

Shift Lever Can Be Moved without Brake Pedal Depressed Column Shift

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: Shift Lock Control Connector End Views or Data Communication Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the shift lock solenoid output control ON and OFF.

Does the automatic transmission shift lock solenoid turn ON and OFF with each command?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

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

Does the test lamp illuminate?

Go to Step 4

Go to Step 10

4

  1. Turn OFF the ignition.
  2. Connect a test lamp between the shift lock solenoid control circuit and the shift lock solenoid ground circuit at the connector of the shift lock control solenoid.
  3. With a scan tool, command the shift lock solenoid output control ON and OFF several times.

Does the test lamp turn ON and OFF with each command?

Go to Step 8

Go to Step 5

5

Does the test lamp remain illuminated?

Go to Step 6

Go to Step 7

6

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

Did you find and correct the condition?

Go to Step 13

Go to Step 9

7

Test the control circuit of the automatic transmission shift lock solenoid for an open or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 9

8

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

Did you find and correct the condition?

Go to Step 13

Go to Step 11

9

Inspect for poor connections at 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 13

Go to Step 12

10

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

Did you complete the repair?

Go to Step 13

--

11

Replace the automatic transmission shift lock actuator. Refer Automatic Transmission Shift Lock Control Actuator Replacement .

Did you complete the replacement?

Go to Step 13

--

12

Important: Perform the set up procedures for the BCM.

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

Did you complete the replacement?

Go to Step 13

--

13

  1. Use the scan tool in order to clear the DTCs .
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK

Shift Lever Can Be Moved without Brake Pedal Depressed Floor Shift

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: Shift Lock Control Connector End Views or Data Communication Connector End Views

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. Apply the parking brake and block the wheels.
  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 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 shift lock solenoid command parameter in the body control module (BCM) data list.

Does the scan tool display ON and OFF status?

Go to Step 4

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Disconnect the electrical connector of the automatic transmission shift lock 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 7

5

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

Did you find and correct the condition?

Go to Step 11

Go to Step 8

6

Press and release the brake pedal several times while observing the brake applied output parameter in the body control module (BCM) output data list.

Does the Scan tool display ON and OFF?

Go to Step 8

Go to Stop Lamps Malfunction

7

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

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

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

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

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

Did you complete the replacement?

Go to Step 11

--

10

Important: Perform the set up procedures for the BCM.

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

Did you complete the replacement?

Go to Step 11

--

11

  1. Use the scan tool in order to clear the DTCs .
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK