GM Service Manual Online
For 1990-2009 cars only

Shift Lever Can Be Moved without Brake Pedal Depressed With Cruise Control

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

1

Did you review the Automatic Transmission Shift Lock Control Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Automatic Transmission Shift Lock Control

2

  1. Turn the ignition switch to the ON position.
  2. Attempt to move the selector lever out of the PARK position. The selector lever should not move out of the PARK position.
  3. Depress the brake pedal.
  4. Attempt to move the manual selector out of the PARK position. The selector lever should move out of the PARK position.

Does the shift lock control operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Exchange the shift lock relay with a known good relay (the horn relay or the compressor relay)
  2. Turn the ignition switch to the ON position.
  3. Attempt to move the manual selector from the PARK position.

Does the shift lock control operate properly?

Go to Step 7

Go to Step 4

4

Disconnect the shift lock relay.

Does the shift lock solenoid disengage?

Go to Step 5

Go to Step 6

5

Test the shift lock relay coil supply voltage circuit for a short to voltage. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

--

6

Test the shift lock solenoid supply voltage circuit for a short to voltage. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

7

Inspect for a poor connection at the harness connector of the shift lock relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

Inspect for a poor connection at the harness connector of the shift lock solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

Replace the shift lock relay.

Did you complete the replacement?

Go to Step 11

--

10

Replace the shift lock solenoid. Refer to Shift Lock Control Solenoid Replacement .

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3

Shift Lever Can Be Moved without Brake Pedal Depressed Without Cruise Control

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

1

Did you review the Automatic Transmission Shift Lock Control Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Automatic Transmission Shift Lock Control

2

  1. Turn the ignition switch to the ON position.
  2. Attempt to move the selector lever out of the PARK position. The selector lever should not move out of the PARK position.
  3. Depress the brake pedal.
  4. Attempt to move the selector lever out of the PARK position. The selector lever should move out of the PARK position.

Does the shift lock control operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Disconnect the stop lamp switch.

Does the shift lock solenoid disengage?

Go to Step 5

Go to Step 4

4

Test the shift lock solenoid supply voltage circuit for a short to voltage. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Inspect for a poor connection at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect for a poor connection at the harness connector of the shift lock solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Adjust or replace the stop lamp switch. Refer to Stop Lamp Switch Adjustment or Stop Lamp Switch Replacement in Lighting Systems.

Did you find and correct the condition?

Go to Step 9

--

8

Replace the shift lock solenoid. Refer to Shift Lock Control Solenoid Replacement .

Did you complete the replacement?

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3