Here's a breakdown of troubleshooting steps, starting with the most likely and progressing to more complex problems:
1. Check the Obvious:
* Brake Pedal: Make absolutely sure you're firmly depressing the brake pedal. Sometimes a worn brake pedal or a problem in the brake light switch can prevent the shift interlock from releasing.
* Ignition: Ensure the ignition is in the "on" (or "accessory" in some cases) position, not just the "accessory" position.
* Steering Wheel: On some vehicles, the steering wheel needs to be unlocked (if it has a locking mechanism). Try slightly jiggling it.
* Shift Lever: Try gently rocking the shift lever back and forth while applying the brake. Sometimes it can get slightly stuck.
2. Shift Interlock System Problems:
* Brake Light Switch: This switch signals the system that the brake is depressed. A faulty switch can prevent shifting. This is a common and relatively inexpensive fix.
* Shift Interlock Solenoid (or cable): The solenoid or cable mechanically releases the shift lever from Park. It might be malfunctioning or stuck. This will require professional diagnosis.
* Wiring: Check the wiring harness connected to the brake pedal switch and the shift interlock system for any damage, corrosion, or loose connections. This is best done by a mechanic familiar with the Sport Trac's wiring diagram.
3. More Serious Mechanical Issues (Less Likely but Possible):
* Transmission Problems: While less likely to cause a complete lock-up in Park, severe internal transmission problems *could* prevent shifting. This is a much more expensive repair.
* Parking Pawl: The parking pawl is the mechanical component that engages to hold the transmission in Park. It might be damaged or stuck. This requires transmission inspection.
* Low Transmission Fluid: Though less likely to cause a complete lock-up, extremely low fluid levels can cause shifting issues. Check your transmission fluid level. (Refer to your owner's manual for location and proper checking procedure).
What to Do:
* Start with the simple checks (brake, ignition, steering wheel, shift lever). If those don't work, move on to the next steps.
* Avoid forcing the shifter. Forcing it could cause damage.
* If the problem persists, it's best to have your 2002 Ford Sport Trac professionally inspected by a mechanic. They have the tools and experience to diagnose the problem accurately and safely. Mention the symptoms clearly – "completely locked in park" – to help them narrow down the cause.
Don't attempt complex repairs yourself unless you have significant automotive experience. Improper repairs can worsen the problem and lead to more expensive damage.
