Direct Electronics Inc. (DEI) manufactured a keyless entry system used by General Motors (GM) dealers for many years. The remote transmitters for this system have FCC ID EZSOEMTX or EZSOEMTX2 on the back. Many people may not even know that this is a dealer-installed system rather than a factory keyless entry system because the keyfob has a “GM” brand button icon on the remote itself. However, if you have a remote with FCC ID EZSOEMTX or EZSOEMTX2 on the back, you should not shop for a replacement remote by the make, model and year (MMY) of the vehicle or buy any factory keyless entry remote because no GM factory remote is compatible with the DEI dealer-installed system, even though some GM remotes look similar.
To see the dealer-installed keyless entry remote, click on this link.
The actual DEI made part has been discontinued; however, there are other DEI 4-button remotes that work interchangeably for it. So, you should still be able to buy and program a remote to work with your vehicle.