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 does not move out of the PARK position with the ignition ON and the brake pedal depressed.

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. Press and hold the brake pedal, 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 hold the brake pedal.
  5. With a scan tool, observe the Shift Lock Solenoid Command parameter in the remote control door lock receiver (RCDLR) data list.

Does the scan tool display an Unlocked status?

Go to Step 5

Go to Step 4

4

With a scan tool, observe the Stop Lamp Status parameter in the body control module (BCM) data list.

Does the brake switch status indicate ON?

Go to Step 8

Go to Stop Lamps Malfunction

5

  1. Turn OFF the ignition.
  2. Connect a test lamp at the shift lock solenoid supply voltage circuit at the connector of the shift lock solenoid 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 10

6

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the automatic transmission shift lock solenoid.
  3. Connect a test lamp between the shift lock solenoid supply voltage circuit and the shift lock solenoid control circuit at the connector of the shift lock solenoid.
  4. Turn ON the ignition, with the engine OFF.
  5. Press and release the brake pedal several times.

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

Go to Step 8

Go to Step 7

7

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

Did you complete the repair?

Go to Step 13

--

11

Replace the automatic transmission floor shift control. Refer to Transmission Control Replacement .

Did you complete the replacement?

Go to Step 13

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12

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

Did you complete the replacement?

Go to Step 13

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13

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2