I have just purchased a C200 Classic Manual 1997. The previous owner allowed the battery to go flat and as a consequence the central locking and alarm are not working and the battery keeps discharging itself.

The hand book does not refer to the small black key I was given with the car. It is a black plastic key with three brass strips on it and it fits into a slot under the driver side dash.

How do I re-set the central locking and alarm with this key?

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