Probably the vacuum pump
only if the car is flashing green and red, but locks are not operating...
that doesnt sound like it is the case here...
Test the remote itself to make sure it is still operational, hold the button for 3-5 seconds, make sure the tip flashes in red.
next, try to resync the key, lock, unlock the driver door with the key blade, put the key in the ingnition, turn to position 2, then off again, then cycle the key blade one more time in the door, while the green light of the door is still flashing green, aim the remote and push the lock switch. the flashing will pause if the car recieves a signal..
at this point, the key must be resynced, and you should be able to lock and unlock normally with the remote.
if the flashing stops (as mentioned above) but the car still does not recognize the key, you either have the wrong remote, or a bad module.