The ignition won't allow you to remove the key when the vehicle is not in PARK, so that means the cable or the cable's jacket is probably not positioned/installed correctly. Where did the cable become disconnected? How did it just come off? Was it at the shifter, or on the bracket next to the transmission oil pan? You need to verify that the cable is installed correctly so that the shifter is all the way in the PARK position when the transmission range selector (on the transmission case) is also in the PARK position. If something is wrong with the cable or jacket, you may need to replace the cable.
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