If you have a owner's manual the directions might be in there. For my 2001 Escape that's where I found the answer
You will need a scan tool to program this Keyless Fob.
You can program a 2001 Chevrolet Camaro by locking then unlocking the door locks.
You can program the keyless entry remote, for your 2001 Saturn L200, by holding the unlock and lock weapons at the same time. The red light will flash on and off. The remote will be programmed when the red light stays illuminated.
see also 2004 silverado
I found an Internet site which says how to program the keyless entry remote. But there is an error: this procedure is good for Elantra 2001 to 2003. Elantra 2004 must be programmed by the dealer. http://car.justanswer.com/hyundai/n1kw-program-remote-entry-hyundai-2004
A keyless entry remote on a 2001 Toyota Sequoia can not be reprogrammed at home. The key must be taken to a dealership where the engineers can program it with new settings.
The dealers scan tool is required.
It requires the dealers scan tool.
If you're asking about adding a NEW keyless remote, only a dealer can do that. It's a very specialized piece of equipment that can add the new remote to your vehicle's computer. If you're asking about RE-programming your keyless remote after replacing the battery, check the inside cover of the remote. It should give instructions on how to solve your problem.
If you have a owner's manual the directions might be in there. For my 2001 Escape that's where I found the answer
See FOB PROG (Remote Keyless Entry Transmitter Programming) on page 2-27 of your "Owner's Manual", under Section 2: Features and Controls - Vehicle Customization Settings.....
Try this: Turn the ignition to RUN (do not start), press the unlock button on the keyless remote, ignition OFF. Repeat 2x. Turn the ignition to RUN, press the unlock button on the keyless remote twice, the power locks should cycle to indicate successful programming. Turn the ignition OFF and test remote.