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 depressed.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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 without pressing the brake pedal.

Does the shift lever move out of the PARK position?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

1. Turn OFF the ignition.
2. Install a scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Ensure the brake pedal is not depressed.
5. With a scan tool observe the Shifter Unlock Fdbk parameter in the body control module (BCM) data list.

Does the scan tool display a LOW status for the brake to shift parameter?

Go to Step 5

Go to Step 4

With a scan tool observe the Brake Switch parameter in the engine control module (ECM) / powertrain control module (PCM) data list.

Does the scan tool display an Released status for the brake switch parameter?

Go to Step 9

Refer to Diagnostic Starting Point - Lighting Systems

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

1. Turn OFF the ignition.
2. Connect a test lamp between the automatic transmission shift lock control solenoid voltage supply circuit and the control circuit of the automatic transmission shift lock control solenoid at the connector of the automatic transmission shift lock control solenoid.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool, command the Brake to Shift Relay output control ON and OFF.

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

Go to Step 8

Go to Step 7

Test the controlled ground circuit of the automatic transmission shift lock control 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

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

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 13

Go to Step 12

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

Did you complete the repair?

Go to Step 13

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

Did you complete the repair?

Go to Step 13

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Important: Perform the setup procedure for the BCM.

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

Did you complete the repair?

Go to Step 13

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2