sorry if u get asked this all the time

ive just bought my 1st gc, the guy i bought it of lost the key an fob, he has a second key an fob but dont seem to work, every time u open the door the alarm just goes off, all so when i unlock the door with the key just the drivers door unlocks, so centrol locking don't seem to to work,

would be so greatfull if anyone could help,

 

not sure if i can be much help but mine does the same thing i did figure out if i unlock passenger door with key and unlock the doors from that side it wont sound the alarm..kind of a pain in the rear but just a suggestion
im sure some more experinced person will chime in just posting on my experince

 

the key cylinder arm/disarm plug fell off on the lock cylinder or went bad.