Here's a breakdown of potential causes within the shift interlock system:
* Shift interlock cable/linkage: This cable connects the shift lever to the transmission. It could be:
* Broken or disconnected: A simple visual inspection can reveal this.
* Adjusted incorrectly: Improper adjustment can prevent the release mechanism from working correctly.
* Stuck or binding: Lubrication might help, but it could also indicate a more serious mechanical problem.
* Brake pedal switch: This switch signals the system that the brake is depressed. If it's faulty, the system won't allow the shift lever to move out of park. The switch can be tested with a multimeter to check for continuity when the brake is pressed.
* Neutral safety switch: This switch prevents the engine from starting unless the shifter is in Park or Neutral. While you can start the engine in neutral, a faulty neutral safety switch *could* still contribute to the problem by improperly signaling the shift interlock system.
* Steering column lock: While less likely, a malfunctioning steering column lock could interfere with the shift interlock mechanism.
* Internal transmission issue (rare): Although less probable given your description, a problem *within* the transmission itself is possible, though it's less likely to explain the specific behavior you're experiencing.
Troubleshooting Steps:
1. Check the brake pedal switch: Make sure it's working correctly. Press the brake pedal and see if the brake lights come on. You can use a multimeter to check the circuit if you're comfortable with basic electrical testing.
2. Inspect the shift interlock cable: Look for any obvious damage, disconnections, or binding. Try gently moving the cable to see if it's free.
3. Try jiggling the shift lever: Sometimes, a little persuasion can help if there's a minor sticking issue. Do this *gently* to avoid damaging anything.
4. Check the shifter linkage: Examine the linkage connecting the shifter to the transmission for any damage or misalignment.
5. Consult a repair manual: A repair manual specific to your vehicle will have diagrams and detailed troubleshooting procedures for the shift interlock system.
Important Note: Starting your engine in neutral is not recommended as a regular practice. While it works around this specific problem, it circumvents a crucial safety feature. Resolve the underlying issue immediately to avoid potential hazards. If you're not comfortable working on your car yourself, take it to a qualified mechanic.
