For 1990-2009 cars

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 lock in the PARK position with the ignition ON and the brake pedal not pressed.
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. 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

3 |

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 Brake to Shift Relay parameter in the body control module (BCM) data list.

Does the scan tool display an ON status for the Shift Lock Control parameter?

Go to Step 5

Go to Step 4

4 | With a scan, tool observe the TCC Brake Switch parameter in the powertrain control module (PCM) data list. Does the scan tool display an OFF status for the TCC Brake Switch input parameter? | Go to Step 9 | Go to Diagnostic System Check - Vehicle
5 |

1. Turn OFF the ignition.
2. Connect a test lamp between the controlled voltage circuit of the automatic transmission shift lock control solenoid at the connector of the automatic transmission shift lock control solenoid and a good ground.
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 several times while observing the test lamp.

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

Go to Step 6

Go to Step 7

6 |

1. Turn OFF the ignition.
2. Connect a test lamp between the ground circuit and the controlled voltage 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 several times while observing the test lamp.

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

Go to Step 8

Go to Step 10

7 | Test the controlled voltage circuit of the automatic transmission shift lock control 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 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 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 control 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 control solenoid. Refer to Automatic Transmission Shift Lock Control Actuator Replacement . Did you complete the repair? | Go to Step 13 | --
12 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the repair? | Go to Step 13 | --
13 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2