Shift lock problem when parked on a hill?

[liteyouup]

I just bought a used 2004 QX56, 100K miles. Everything seems to work great except one thing. If I park on a hill, or even my driveway, the shift lock won't let me shift into gear. Where should I start as far as fixing the problem?

 

[2011qx]

When you put any car into park, always stop the car, keeping the tranny in drive, but don't take your foot off the regular brake. Then apply the parking brake and then let your foot off the regular brake to make sure the parking brake is properly engaged. If it is properly engaged, then put the truck into park and take your foot off the regular brake and you are good to go. In essence the emergency brake is taking the strain of the vehicle on the hill and not the tranny.