For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
DEFINITION: The ignition lock cylinder will not allow the key to be turned to the LOCK position.
1 | Did you review the Steering Wheel and Column-Tilt Description and Operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Steering Wheel and Column - Tilt
2 | Verify that the lock system does not lock. Does the lock system lock? | System OK | Go to Step 3
3 | Inspect the lock cylinder case for damage. Is the lock cylinder case damaged? | Go to Step 13 | Go to Step 4
4 | Inspect the lock cylinder for damage. Is the lock cylinder damaged? | Go to Step 14 | Go to Step 5
5 | Inspect the ignition switch for damage. Is the ignition switch damaged? | Go to Step 15 | Go to Step 6
6 | Does the vehicle have an automatic transmission? | Go to Step 7 | Go to Step 2
7 | Verify the Automatic Transmission Shift Lock Control operates properly. Refer to Automatic Transmission Shift Lock Control Description and Operation in Shift Lock Control. Does the Automatic Transmission Shift Lock Control operate properly? | Go to Step 8 | Go to Symptoms - Automatic Transmission Shift Lock Control in Shift Lock Control
8 | Test the ignition lock cylinder solenoid supply voltage circuit for battery voltage. Refer to Circuit Testing in Wiring Systems. | Go to Step 10 | Go to Step 9
9 | Test the ignition lock cylinder solenoid supply voltage circuit for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 11
10 | Test the ignition lock cylinder solenoid ground circuit for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 12
11 | Replace the shift lock control module. Refer to Shift Lock Control Module Replacement in Shift Lock Control. Did you complete the repair? | Go to Step 16 | --
12 | Replace the ignition lock cylinder solenoid. Refer to Ignition Lock Cylinder Solenoid Replacement - On Vehicle . Did you complete the repair? | Go to Step 16 | --
13 | Replace the lock cylinder case. Refer to Ignition Lock Cylinder Case Replacement - On Vehicle . Did you complete the repair? | Go to Step 16 | --
14 | Replace the lock cylinder. Refer to Ignition Lock Cylinder Replacement - On Vehicle . Did you complete the repair? | Go to Step 16 | --
15 | Replace the ignition switch. Refer to Ignition Switch Replacement - On Vehicle . Did you complete the repair? | Go to Step 16 | --
16 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2