I have a 2008 Diplomat and my keyless remote did not work. I found the unit under the center cabinet between the driver and passenger seat. I pushed the reset, checked for power to the unit. Everything checked out. I put the remote close to the unit and it worked. When I got farther away it stopped working. Lon story the new battery I put in the remote was bad. New battery and it has been working great.
2008 Monaco Diplomat 40 PDQ