Owners/service Manual problems of the 2005 Infiniti FX35

I noticed the locks on both back seat doors, passenger front seat and back door were not locking/unlocking using the remote. The only way to lock and unlock all doors (excluding the driver's side door) is manually. Intermittently, the rear gate does not unlock. Apparently this is a common problem with that make, model and model year. Is the dealer responsible for this repair since it's under 500 miles and it started happening after purchase, if not before.