My Trailblazer shifter started getting stuck in park around the 90K mile mark. Dealer diagnosed the problem as the neutral safety switch (after replacing the solenoid & eventually the entire shifter). Problem occurred again several times within 5K miles and 2 more NSS were tried. Eventually the dealer mechanic cleaned up a ground near the NSS and problem went away until now. Vehicle is now at 116K miles.
I went to back out of a parking spot and shift to drive but it stayed in reverse. Found that the shift selector cable bushing had broke and came
Loose. It was a $10 part and took me less than 15 minutes to install. Had to use a set of ramps so I could fit under the truck and a pair of channel locks to snap the two back together.
Got stuck in Dallas on a Sunday. Got gas, put car into drive and attempted to drive forward but went in reverse instead. Fortunately I found a Firestone that was open and they sent a flatbed to get me. Seems as though the Gear shift cable went out. That was costly at over $1000 to get fixed and an overnight stay plus a days vacation.
My trailblazer died and the shifter was stuck in park while the dash said it was in reverse. My husband is a mechanic and he identified the transaction line was broken where it connected to the shifter.
The bushing needs replacing. This is a plastic or metal clip the connects the interior gear shifter to the linkage that is on the underside of the truck. This is a tricky issue. If you go to put the vehicle in gear and it is loose that means the 2 parts have come a loose. Your linkage may be in one gear and the interior shifter in another...AND you may put the interior shifter in park, unconsciously. If you do you will have to line to 2 parts up. If you are not brave, mechanically inclined or vehicle savvy, Do Not attempt to Band-Aid or fix yourself.