My 2010 Grand Caravan has a Keyless entry issue 90% of the time. Had it in under warranty twice. The dealer denies any problem exists. I'm sick of these guys. They say they can't re-create the problem, but I re-create it 25 times a day! I'm of pressing the unlock button a million times to get the dadburn thing to unlock or lock!! It's obviously a wireless RF issue with the transmitter, receiver and/or the brain that interprets the recieved signal and sends a pulse out to the solenoids. The inside button works 100% of the time.
The bottom line is they wont spend the money to resolve the issue under warranty.
No wonder why Toyota and Hundai are taking over the world.

 

Does the other controler do the same thing ?
Have you tried the obvious replacing the battery and cleaning the switches?