i'm having the same problem...
help- keyless entry stopped working!
Everything functions properly for me when i use the key in the lock. See if yours does as well. Hopefully we can find someone who has had this happen to them and find out what the fix was and how much it cost!!! (ie: I may be doing it manually from now on!)
In my younger diy days (when things were less computerized), I recall a flathead screwdriver adjustment inside the remote on an old Ungo Box alarm I had. It needed occasional adjustment to sync with the brain unit for optimum performance (dial in for strongest signal). ...I doubt it's that easy anymore!