I see this post is dated but I'm having the same issue with the button not releasing. My problem started as a button that got slightly harder to push over a two week period until it became unmoveable until you smack it with the heal of your hand. I am mechanically minded, electrically I have no experience. In the electrical diagnosis it says to use a test lamp. What is this? I want to fix it myself if possible. Let me get one other thing straight. The location of the Park Lock Solenoid is in the steering column and the Shift Lock Control Solenoid and Switch are down on the floor shifter? I have a 98 Jimmy. I did also notice that when the key is turned to the on position on the passenger side base of the shifter a thin metal rod with a round disc on the end of it pops out toward the passenger side. TIA for any help or suggestions.

Steve