Nissan Titan stuck in park

check to see if the parking brake is stuck,

find the shift lock solenoid override (if applicable),

If parked on a hill the force of gravity could be forcing your transmission

to put pressure on the parking lock in the transmission.

you will need to rock the vehicle.

from the driver’s seat. Just throw your weight around.

This will take pressure off of the parking lock.

Apply light pressure to the shifter

The shift lock solenoid keeps you from shifting out of park

without your foot on the brake.

May have an override button.

Check for a cosmetic plug (pop it out)

May have bad brake light switch.

Check to see if brake lights come ON

May have bad fuse

May be bad ignition switch