I actually just got a keyless installed the other. Appearently it isn't so straight forward because the central locking module on our cars utilizes a pulse for lock and unlock. I believe it is two pulses for unlock and one for lock. or something like that.

Anyways, he installer told me that you are required to get an additional module that will translate the central locking signal from your car alarm in a pulse.

That's all i understood. I usually keep far away from electrial stuff in my cars.

Cheers,
Augy