Can anyone describe the procedure for reprogramming a "forgotten" key fob so it can be recognized by the alarm system in the Roadster Sport? I would like to avoid a service visit just to reprogram a "Maytag-ed" key fob.
I don't think you're going to avoid a service visit. You'd need to know your car's security code - start with calling the service center and seeing if they'll give you the info you need to reprogram. But I'm betting you'll need to bring the car in.
I once helped my Ranger reprogram my fobs, because he was having trouble doing it alone. The procedure is ridiculously elaborate, involving a crazy sequence of strange actions to initiate it, then watching a light blink and turning the key when it reaches the right number, repeatedly, to enter the key's fairly long ID number. (For all I know the method is different for American cars... but probably just as obscure.)
All I know is that when they were going to reprogram my key, no one could find the security code (should have been in the system) and they ended up having to replace a component in the car because of the missing security code and also wait for a the reprogrammer to show up at the service center. It was an ordeal and no one was happy about it, least of all the service center. Doug_G is right, it's ridiculously elaborate.
I needed a new key and they only sell in a packeage with two FOB keys and the receiving unit. I just wanted the key and so I swapped key parts. But if you buy the kit (about $70) the receiving unit is under the dash and unfortatenly you have to pull the instrument cluster to reach it. Not impossible but a couple hour operation if you have not done it before.
The silver lining in replacing the receiver unit in the dash is that you get to run the antenna wire away where you want it. Tesla had to replace my unit, and the tech was very willing to route the antenna wire on its own.
Before this, my fob, with new batteries, would only work when I could physically reach the key hole at the rear.
Now, it's like a normal car remote's range. Unbelievable that that factory did something so stupid in the first place, but I smile when I use my remote now.