A site visitor recently inquired about a replacement remote for his 2003 Toyota Tundra truck. As it turns out, his vehicle did not have a factory keyless entry system; instead, it had a Toyota port-installed system that originally used a remote with FCC ID ELVATDC on the back.
Prior to the years when factory keyless entry systems became standard equipment on nearly all new vehicles, Toyota often added port-installed or dealer-installed alarm/keyless entry systems to vehicles for the benefit of North American customers who wanted the security or convenience of a system.
Through the years, these add-on systems used a number of different remote transmitters, one of which was a 3-button keyfob with a red LED light and the FCC ID ELVATDC on the back. That remote is no longer made, but Toyota does offer a newer remote that replaces it. That keyfob is Remotes Unlimited part 092-6435, which looks similar but has a green LED light and FCC ID ELVATDD.
You can see and purchase the new remote at this link:
RUI part 092-6435
This remote is user programmable.