lock the van and with the keyfob near the window, press the 'LOCK' button and hold for 30 seconds.
try unlocking the van with the keyfob, if it doesn't, unlock the van with the key and press the 'UNLOCK' button for 30 seconds. I just cannot remember which way the vehicle has to be, (Locked or unlocked), but this should recode the fob.
Davymac, December 2009