Programming mercedes remote

I recently purchased a 1990 Mercedes 500SL.  It came without a remote for the keyless entry.  Now I have acquired a used remote.  Can anyone advise as to if the used remote can be programmed for this vehicle?  And, if so, does anyone know the programming sequence?  Many thanks.  Gene

Dear Gene, Just so you know the Mercedes Benze brand have used one of many variations of the secure key. The first iterations was the simple resistive keys such as the ones from GM / Ford style. Which have a simple fixed resistive value. The second generation was in the form of the magnetic resonance type. Which is based on the amount of flux / magnetic field it produced to deactivate the system. The third generation uses a IR type of laser diode to deactivate the system, along with a mag style. All keys are vehicle specific, and your best method to make all features opperate accordinly is to purchase the key from an authorized dealer. No doubt it will costs aprox. $125-150.oo USD for the key. A universal key cannot be made to be learnt in the 2 second / third generation vehicles, without REPO techniques and hardware. If the key simply needs to be *resynced* then you will need to aim the remote and press the botton that arms / disarms the system and go from there. Just so you know one of the transponders is a fixed code, one is a rolling code in the newer models. The transponders operate without any battery power at all, the batteries that are for remote lock/unlock only, and also for the convenience features (rolling up and down of windows and sunroof, which is an IR function. Regards EVIL Teken...