I have to change my ECU on my 2002 C2. Do I have to get the keys reprogrammed?

 

You should not have to if they program the ECU with the same IPAS codes from the Alarm.

 

The keys have been programmed to an ECU that the diagnostics are pointing to as having an error. So, I have another ECU, but if I have to reprogram the keys for $200, I'll live with the error. It sounds like if I use this other ECU, I'll have to have Porsche reprogram it again. Correct?

 

What type or error do you get on original ECU? If you change the ECU for a different one yes the ECU will need to be reprogrammed by a shop, but the keys you are using now should work.

 

The keys are programmed to the alarm/immobilizer module, not the ECU (DME).

A replacement DME will be programmed with the same immobilizer and DME codes that your car originally had, and therefore you would not need to reprogram keys.

If you replace the immobilizer module then it's codes must match with whatever the DME has (new or old).