I have a GTV6 and a Gearbox from a Milano with the newest sender on it. Now I have the Milano's amplifier for the signal coming from the gearbox' sender

, but I don't know what kind of signal is coming out of it and what kind is the speedometer waiting for. Anybody can help?
I'm certain that it's rather easy to fix, but I haven't got the knowledge.
Thank you beforehand.
P.S.: I have an old osciloscope in case it was needed