I have the same problem on 2009 Eddie Bauer Explorer w/center console shifter. Once in a Blue Moon it will get stuck in Park. I took my cc completely apart and cleaned everything. The shift lock solenoid works perfectly when you press on the brake. I know how to remove the cup holder, remove the plug and press down on the "thingy" on the rare occasion it gets stuck in park, but I can see it is already in the down and unlock position...in other words, no help! It has occurred maybe 5 to 6 times in past year. Usually it occurs on an incline, but once it occurred on flat level surface! I can usually keep playing with it and eventually it will come out of park.
It appears to me the shift solenoid and that little black plastic "lock thingy" only locks the shifter movement in the console! Once the shifter console lever is unlocked there, it frees the shift lever to move the control cable that goes directly to the shift lever on the left side of the transmission. When my console shifter normally moves from P to R (the first inch of travel), it allows the park pawl in side the tail housing of the transmission (engaged when in park) to spring to the unlocked position. My problem is, the shift in the console unlocks, moves half way to R but meets resistance to go any further! In other words, the shifter is unlocked in the console, but for some reason, the shift cable force cannot move the lever on the left side of the transmission to allow the park pawl to drop out and unlock itself form the slotted park pawl gear?
The last 2 times it occurred, I had the console cover off and verified the shift solenoid was working and the "black lock thingy" was in unlock position when brake pedal was depressed I then had my son rock the car while I held the "black thingy" open manually (YOU CANNOT PRESS THE BRAKE PEDAL TO DO IT, BECAUSE YOU CANNOT ROCK THE CAR WITH THE BRAKE ON!). With the brake OFF and the console lock manually held OPEN/UNLOCKED, yes he was able to rock the car and with some force, the shifter moved freely out of park and into reverse and on to all other gear positions!
This does not happen very often AND I have parked on steep hills and 99% of the time it will not happen...BUT once in a while it will. My first thought is the little spring on the park pawl is weak or broken, but then why doesn't it do it more often? Is the park pawl worn? I can see there are about 24 to 28 notches in the park pawl ring gear, making me think there my be only 1 or 2 of these notches that may be worn or damaged to the point the park pawl cannot slide out IF ones of these notches is randomly selected...that would explain the randomness!
All that said, if anyone out there has experienced this problem or has comments....please reply! THANKS!