2008 Buick Lacrosse latches & locks problems

Remote, remote starter (rke) fob for car stopped working properly. Replaced batteries even though dic did not show batteries needed changing. This maybe a problem also. Sometimes it works, sometimes it doesn't. Worked perfectly fine, then problems started. 99% of the time it will not start the car. 50% of the time it will or will not, lock or unlock car. I have tried resetting and/or personalizing keys & fob through dic center. Car will sound horn to show it has been reset properly, but isn't.

The passenger power door lock fails to un-lock or lock when accessed with the key fob. The malfunction recurred sporadically. When putting vehicle into drive (or when vehicle is turned off) the door doesn't lock or unlock on the passenger side. Other door locks are starting to have same problem. The mileage of vehicle was 27,000 and door lock problems began march 17, 2014.