Are you sure that the radio is asking you for a code?
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This stereo is electronically paired, or "Married" to the engine management system of the vehicle it came out of using very sophisticated MOST-BUS system technology.
When it is first powered up, it will communicate with the vehicle, and a message of "PORSCHE" will appear on the display whilst this process is in operation. If communication has been successfull, it will then operate in the normal way.
However, if removed and refitted into a different vehicle other than the original one, it will not recognise the encrypted MOST-BUS identification of the new car, and will instead display an error message of "PROTECT" after around 30 seconds.
This Radio cannot therefore be transferred from one car to another, unless it has first been reset back into its original "Delivery Mode" with the internal MOST-BUS data memory reprogrammed for use with the new vehicle.
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So you need to drive to your dealer and ask if they can reset the system and 'marry' the radio to your car.
A.R.S., November 2012