It is probably obvious that vehicle manufacturers identify every part associated with a car or truck with a part number. This is true for keyless entry remotes. What is not so obvious is the logic with which they do this. In fact, when you dig into the world of OE part numbering, you find that the logic they use is not always so logical.
For example, we know of one 3-button, peanut-shaped keyfob remote transmitter used on Chyrsler and Dodge vehicles in the 1990s that was assigned all 8 of the following OE manufacturer part numbers: 05014736AA 04686076 56008761 56008762 56021903AA 56021903AB 56036843 56036844. The remotes bearing these numbers are functionally and cosmetically identical in every respect.
This OE part number proliferation means that it is very difficult for any replacement remote vendor to assemble all of the reference data associated with a part that they sell. Still, if you know the OE part number of your original keyless entry remote, searching for a replacement keyfob by the OE manufacturer part number is a very good idea because it is the most definitive part identifier. The peanut-shaped keyfob referred to above, for example, has look-alike “brother remotes” with the same FCC ID that are not compatible with it. So, whenever buying a keyless entry car remote online, it is best to search based on the OE part number or make, model and year of the vehicle.