* Check your key: Is it the correct key? Try all keys you have. Is the key worn down or damaged? A slightly damaged key can fail to properly engage the tumblers.
* Steering Wheel Lock: Is the steering wheel locked? Try gently jiggling the steering wheel while turning the key. Sometimes the lock mechanism binds.
* Shift Lever Position: Ensure the car is in Park (for automatic) or Neutral (for manual). The ignition won't turn unless it's in the correct gear position.
* Battery: A weak battery can sometimes prevent the ignition from turning. Try jump-starting the car. If this works, your battery might need replacing.
* Wiring Issues: A less common possibility is a problem with the wiring to the ignition switch. This is more difficult to diagnose and requires checking the wiring harness.
* Ignition Switch (separate from the cylinder): The ignition switch itself can fail independently of the lock cylinder. This is another internal component that can cause the problem, but replacement is also involved.
If none of the above work:
* Professional Diagnosis: A qualified mechanic can diagnose the issue more accurately. They have specialized tools to test the ignition system and can determine if it's truly the lock cylinder or something else. This is recommended *before* buying and installing a new cylinder.
Replacing the ignition lock cylinder is a last resort because it's involved and requires precise work to avoid damaging other components. Getting a professional opinion will save you time and money in the long run.
