A while back our keyless entry and door locks spontaneously stopped working on our 2005 Dodge Caravan.  With a little research, I found that if one disconnects the negative battery terminal for five minutes or longer (if you leave it off less than 5 minutes it won’t completely drain the computer of power), the locks and keyless entry will work again.  Apparently there is a computer-chip program hiccup or glitch that needs to be cleared out by shutting off its power supply.  This normally won’t happen often, but when it does, I have found it much cheaper and handier to quickly get the keyless entry and locks working in this way than with a trip to the mechanic.  You may feel that a >$200.00 trip to the dealership/mechanic is better for you; by all means, go.  However, this DIY method can get one out of a jam, and may hold for months at a time. 

Some say another quick solve is to remove the 20 amp fuse on the lower left of the fuse box.  If there are two, one vertically oriented and one horizontally, remove both for five minutes.   One of these is supposed to be the fuse for the Body Control Module, and removing it to have the same effect as the negative battery cable;  I have had consistent success with removing the cable.  The Body Control Module, referred to as BCM (as is the acronym for the Battery Control Module), controls electrical items like power windows, door locks, the instrument panel cluster, all sensors and troubleshooting or engine fault, fail or error code generation, etc.  Some automotive website forum participants say that dealers may tell you a new BCM is needed for $400.00 after they bill you for “finding it out.”   Others say dealers may tell you a downloaded code fix will resolve the issue, and charge up to $250.00 for that.  Personally, I would rather remove the cable or the fuses, which some find simpler than removing the negative battery cable.

Generally, a wrench size from 10 mm. (3/8 in.) to 13 mm. (1/2 in.) will fit the nut holding the cable end to the battery terminal; simply loosen to remove, safely setting the cable away from the battery terminal for five minutes or longer, then firmly push the cable end down to retighten and secure the negative battery cable again.   “Voila”!  Your keyless entry and electric door locks work again.  Remember to correctly reset your vehicle’s clock and radio selections.