I had an interesting conversation with a customer today about how difficult it is to specify replacement remote key fobs for factory keyless entry and aftermarket alarm systems. Many factors contribute to this challenge, not least of which is the proliferation of part numbers and FCC ID numbers out there.
Vehicle manufacturers make specification much more difficult by using multiple identifying numbers on the same part. We know of many Chrysler, Ford and GM factory keyless entry remotes that have ten or more part numbers associated with them.
FCC ID numbers are somewhat more useful. However, we know of circumstances where equivalent remotes have different FCC ID numbers and non-equivalent keyfobs that have the same FCC ID number. The common Ford 3-button and 4-button remotes have had at least 5 different FCC IDs. The most common are GQ43VT11T and CWTWB1U331. How many others can you name?
If you are buying a replacement car remote, you may find it far more complicated than it should be.