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 Computer/Integrating Systems Connector End Views in Computer/Integrating Systems

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 in Vehicle DTC Information

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 thew PARK position?

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

Go to Step 3

3

  1. Disconnect the automatic transmission (A/T) shift lock control switch.
  2. Turn ON the ignition, with the engine OFF.
  3. Press and hold the brake pedal.
  4. Attempt to move the transmission shift lever out of the PARK position.

Does the transmission shift lever move out of the PARK position?

Go to Step 5

Go to Step 4

4

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

Does the transmission shift lever move out of the PARK position?

Go to Step 7

Go to Step 6

5

  1. Inspect for proper A/T shift lock control switch adjustment. Refer to Stop Lamp Switch Adjustment in Lighting Systems.
  2. Inspect for poor connections at the harness connector of the automatic transmission shift lock control 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 10

Go to Step 8

6

Inspect for poor connections at the harness connector of the A/T shift lock control 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 10

Go to Step 9

7

Repair the short to battery positive voltage in the A/T shift lock control solenoid supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

--

8

Replace the A/T shift lock control switch. Refer to Stop Lamp Switch Replacement in Lighting Systems.

Did you complete the replacement?

Go to Step 10

--

9

Replace the A/T shift lock control solenoid. Refer to Automatic Transmission Shift Lock Actuator Replacement .

Did you complete the replacement?

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3