The "stuck in park" issue on these cars is a common problem and usually stems from one of the following:
* Faulty Shift Interlock Solenoid: This is the most likely culprit. The solenoid receives an electrical signal to release the park lock mechanism when you press the brake pedal and move the shifter. If the solenoid is weak, faulty, or receiving a bad signal, it won't release. This requires replacement, not adjustment.
* Brake Pedal Switch: The switch senses when the brake pedal is pressed and sends the signal to the solenoid. A faulty switch won't send the signal, leaving the car stuck in park. This needs to be tested and replaced if faulty.
* Wiring Issues: Corrosion, broken wires, or poor connections in the wiring harness related to the brake pedal switch or solenoid can interrupt the electrical signal. This requires careful inspection and repair of the wiring.
* Shift Lever Cable (or Linkage): While less common, issues with the shift cable or linkage can prevent the mechanism from releasing, even if the solenoid is working correctly. This would involve checking for binding, breakage, or adjustment (although adjustment is usually not a significant factor).
* Internal Mechanism Wear: Over time, the internal parts of the shift interlock mechanism can wear out and fail to disengage properly. This usually requires replacement of the entire mechanism.
How to troubleshoot:
1. Check the brake lights: If your brake lights don't work, the brake pedal switch is likely the problem. Replace it.
2. Test the brake pedal switch: You can test it with a multimeter to see if it's sending a signal when the brake pedal is pressed. (Consult a wiring diagram for the correct terminals).
3. Inspect the wiring: Look for any obvious signs of damage, corrosion, or loose connections in the wiring harness related to the brake pedal switch and shift interlock solenoid.
4. Try tapping the shifter: Gently tap the shifter around the P position while depressing the brake pedal. Sometimes, a slight nudge can dislodge a sticking mechanism. (Avoid forceful attempts).
5. Check the solenoid: Accessing and testing the solenoid is more involved and usually requires some disassembly. This usually involves removing the center console or other interior panels to get to the solenoid. Testing might involve applying 12V directly (carefully, with the correct polarity and only momentarily) to see if the mechanism releases. If it does, the solenoid is faulty.
Important Note: Before attempting any repairs, disconnect the negative battery terminal. Working on the electrical system requires knowledge and caution. If you are not comfortable with electrical work or mechanical repair, take your Cadillac to a qualified mechanic. Attempting repairs without proper knowledge can lead to further damage or even injury.
