* Steering Wheel Lock: This is the most common cause. The steering wheel may be slightly locked, preventing the key from turning. Try gently jiggling the steering wheel back and forth while trying to turn the key.
* Shift Lever Not in Park (Automatic Transmission): Make absolutely sure the gear selector is firmly in the "P" (Park) position. Sometimes it can feel like it's in park but isn't fully engaged.
* Faulty Ignition Switch: This is a more serious problem. The ignition switch itself might be worn out, damaged, or malfunctioning. This often requires replacement.
* Broken Key: A worn or damaged key can prevent it from engaging properly with the ignition cylinder. Try a spare key if you have one.
* Steering Column Issues: Problems with the steering column lock mechanism can prevent the key from turning.
* Broken Ignition Cylinder: The cylinder itself might be damaged or worn, preventing the key from turning.
* Low Battery: A very weak battery *can* sometimes affect the ignition system, although this is less common.
Troubleshooting Steps:
1. Try the spare key: This immediately tells you if the problem is with the key itself.
2. Check the steering wheel: Gently jiggle the steering wheel while trying to turn the key.
3. Verify the gear selector: Make absolutely sure the car is in Park.
4. Check the battery: While less likely, a very weak battery can sometimes cause this issue. Try jump-starting the car (with proper safety precautions).
If none of the above solves the problem:
You'll likely need professional help. A locksmith or mechanic can diagnose the issue more accurately. They can determine if it's a simple fix (like replacing the ignition switch) or something more involved (like a steering column problem). Attempting more advanced repairs yourself could cause further damage.
