If the vehicle is equipped with an automatic transmission , it has a ignition lock cylinder control actuator system in the steering column. The ignition lock cylinder control actuator's purpose is to prevent the ignition key from being turned to the OFF position when the transmission is in gear. The ignition lock system consists of a ignition lock cylinder control actuator and a park position switch that is located in the A/T shift lock control switch. The ignition lock cylinder control actuator contains a pin that is spring loaded out to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column.

Schematic Reference

Power Distribution Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Steering Wheel and Column Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, engine OFF, observe the scan tool while moving the gear shift lever through all gear ranges. The parameter on the scan tool should match the gear that is selected on the gear shift lever.

⇒	If the gear selection does not match refer to Range Selector Lever Link Adjustment for range selector lever link adjustment.

2. Verify that the ignition key can be turned from the OFF position to the CRANK position.

⇒	If the ignition key cannot be turned refer to Ignition Lock Cylinder Replacement Ignition Lock Cylinder Replacement.

1. Ignition ON, engine OFF, verify a test lamp illuminates between the key lock actuator B+ circuit harness connector terminal A and ground.

⇒	If the test lamp does not illuminate test the B+ circuit for an open/high resistance or a short to ground.

2. Ignition On, engine OFF and the gear selection lever in PARK. Verify a test lamp illuminates between the key lock actuator B+ circuit harness connector terminal A and the key lock actuator control circuit harness connector terminal B.

⇒	If the test lamp does not illuminate test the control circuit for an open/high resistance. If all circuits test normal replace the ignition switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.