The body control module (BCM) controls voltage to the ignition lock cylinder actuator. When the gearshift is in PARK, the park position switch is closed. This grounds the circuit allowing the lock cylinder actuator to retract the pin. This allows the ignition lock cylinder to be turned to the LOCK position. When the gearshift is not in PARK, the park position switch is open, and the spring loaded pin is in the out position. This prevents the ignition lock cylinder from being turned to LOCK.

Schematic Reference

Ignition Lock Schematics

Connector End View Reference

Master Electrical Component List

Description and Operation

Electronic Park Lock Description and Operation

Electrical Information Reference

1. Ignition OFF, disconnect the harness connector at the park switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.

⇒	If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition OFF, disconnect the harness connector at the ignition lock cylinder control actuator.
4. Ignition ON, verify a test lamp illuminates between the control circuit terminal B and ground.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. Connect a test lamp between the control circuit terminal A and the control circuit terminal B.
6. Ignition ON, cycle the gear shift from PARK to DRIVE. The test lamp should turn ON and OFF when cycled between gears.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If circuit tests normal, replace the park switch.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the park switch.

7. If all circuits test normal, replace the ignition lock cylinder control actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

The body control module (BCM) controls voltage to the ignition lock cylinder actuator. When the gearshift is in PARK, the park position switch is closed. This grounds the circuit allowing the lock cylinder actuator to retract the pin. This allows the ignition lock cylinder to be turned to the LOCK position. When the gearshift is not in PARK, the park position switch is open, and the spring loaded pin is in the out position. This prevents the ignition lock cylinder from being turned to LOCK.

Schematic Reference

Master Electrical Component List

Connector End View Reference

Master Electrical Component List

Description and Operation

Electronic Park Lock Description and Operation

Electrical Information Reference

1. Ignition OFF, disconnect the harness connector at the park switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.

⇒	If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition OFF, disconnect the harness connector at the ignition lock cylinder control actuator.
4. Ignition ON, verify a test lamp illuminates between the control circuit terminal B and ground.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. Connect a test lamp between the control circuit terminal A and the control circuit terminal B.
6. Ignition ON, cycle the gear shift from PARK to DRIVE. The test lamp should turn ON and OFF when cycled between gears.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If circuit tests normal, replace the park switch.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the park switch.

7. If all circuits test normal, replace the ignition lock cylinder control actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming