When my truck is in park it will not go out of park. It take like 10 minutes of wrestling with the shifter to eventually get it into gear. This just randomly started happening out of no where and is very irritating.
Your BTSI Solenoid, Brake Transmission Solenoid Interlock, may be intermittent. It stops you from getting the shift lever out of Park without the key. You have the key in the on position, push on the brake which activates the solenoid. It could also be the brake circuit that activates it. Check for voltage to the dark green/white wire to the BTSI solenoid with the key on and the brake pedal depressed.If there is good voltage then I would replace the BTSI solenoid. If there is no voltage then the stop lamp switch or park/neutral switch would be suspect. This YouTube video shows how to get at it. The guy mentions leaving it out but that would let anyone move the shift lever out of park anytime.