My Boxster's electrical system is screwed up.

[Wilson95005]

If I buy a new immobilizer, will that need to be reprogrammed by a dealer? If so, any idea how expensive, ball park?

What will work after installing a new immobilizer? Will the engine even start before reprogramming?

Also, how big a job is removing the driver's seat to get to the area? If I go the EcuDoctors route, I might have a try at it.

[Cbonilla]

Removing the seat is no big deal. Four torx head screws. If you don't have a female Torx socket a standard socket will work and not bigger the screw heads too badly. Disconnect the battery first or you will trigger an air bag light. The hardest part is figuring out how to undo the plug from the seat into the immobilized. If I recall correctly, you have to lift and remove a tab and then slide the plug apart. May be able to find a video on how to open this

[78F350]

Originally Posted by Wilson95005

If I buy a new immobilizer, will that need to be reprogrammed by a dealer? If so, any idea how expensive, ball park? What will work after installing a new immobilizer? Will the engine even start before reprogramming? ...

A New immobilizer will have to be reprogrammed. Three parts work together: the transponder in the key fob, the Central locking unit (immobilizer box under the seat), and the DME (engine computer in the rear trunk). All three of those parts have to have a matching code for the car to start. The only part that can be electronically reprogrammed is the DME, so if you just swap one of the three, your car will not start.

Three alternatives to a new box and reprogramming:

-ECU Doctors can repair your central locking unit (CLU).

-A smart electronics tech can take the part of your CLU that has the immobilizer code and swap it into a good unit. *edit: I don't think this would fix your fob button issues.

-You can get a complete set of key fob, CLU, and DME from a similar year/model car and swap it together into your car. The minor issue with this is that the DME will retain the data from the donor car (such as VIN, over revs, hours... ) unless it is reprogrammed to your car's data.
I have a set from a 2001 base: 1 fob, CLU, DME. PM me for price if you want to try that route.